diff --git a/README.md b/README.md
index 740163d..e151aff 100644
--- a/README.md
+++ b/README.md
@@ -761,6 +761,8 @@ If get this, Congratulations!
 <details><summary>Must use `var` to define variables</summary> 
 
 This interpreter uses more strict syntax to make sure it is easier for you to program and debug.
+And flightgear's nasal interpreter also has the same rule.
+So do not use varibale without using `var` to declare it.
 
 In Andy's interpreter:
 
@@ -794,32 +796,6 @@ code: undefined symbol "i"
 
 </details>
 
-<details><summary>Default dynamic arguments not supported</summary>
-
-In this interpreter,
-function doesn't put dynamic args into vector `arg` by default.
-So if you use `arg` without definition,
-you'll get an error of `undefined symbol`.
-
-```javascript
-var f=func(){
-    println(arg)
-}
-f(1,2,3);
-```
-
-Compilation result:
-
-```javascript
-code: undefined symbol "arg"
- --> test.nas:2:15
-  | 
-2 |     println(arg)
-  |               ^ undefined symbol "arg"
-```
-
-</details>
-
 ## __Trace Back Info__
 
 ![stackoverflow](./doc/gif/stackoverflow.gif)
diff --git a/doc/README_zh.md b/doc/README_zh.md
index a721005..90ee530 100644
--- a/doc/README_zh.md
+++ b/doc/README_zh.md
@@ -735,6 +735,7 @@ dylib.dlclose(dlhandle.lib);
 <details><summary>必须用 var 定义变量</summary>
 
 这个解释器使用了更加严格的语法检查来保证你可以更轻松地debug。这是非常有必要的严格，否则debug会非常痛苦。
+同样的，flightgear 内置的 nasal 解释器也采取了类似的措施，所以使用变量前务必用 `var` 先进行声明。
 
 在Andy的解释器中:
 
@@ -762,29 +763,6 @@ code: undefined symbol "i"
 ```
 </details>
 
-<details><summary>默认不定长参数</summary>
-
-这个解释器在运行时，函数不会将超出参数表的那部分不定长参数放到默认的`arg`中。所以你如果不定义`arg`就使用它，那你只会得到`undefined symbol`。
-
-```javascript
-var f=func(){
-    println(arg)
-}
-f(1,2,3);
-```
-
-编译结果:
-
-```javascript
-code: undefined symbol "arg"
- --> test.nas:2:15
-  | 
-2 |     println(arg)
-  |               ^ undefined symbol "arg"
-```
-
-</details>
-
 ## __堆栈追踪信息__
 
 ![stackoverflow](../doc/gif/stackoverflow.gif)
diff --git a/src/nasal_builtin.cpp b/src/nasal_builtin.cpp
index 3f0326f..a097810 100644
--- a/src/nasal_builtin.cpp
+++ b/src/nasal_builtin.cpp
@@ -1210,12 +1210,6 @@ var builtin_millisec(var* local, gc& ngc) {
     return var::num(res);
 }
 
-var builtin_sysargv(var* local, gc& ngc) {
-    var res = ngc.alloc(vm_vec);
-    res.vec().elems = ngc.env_argv;
-    return res;
-}
-
 var builtin_gcextend(var* local, gc& ngc) {
     var type = local[1];
     if (type.type!=vm_str) {
@@ -1356,7 +1350,6 @@ nasal_builtin_table builtin[] = {
     {"__costatus", builtin_costatus},
     {"__corun", builtin_corun},
     {"__millisec", builtin_millisec},
-    {"__sysargv", builtin_sysargv},
     {"__gcextd", builtin_gcextend},
     {"__logtime", builtin_logtime},
     {"__ghosttype", builtin_ghosttype},
diff --git a/src/nasal_builtin.h b/src/nasal_builtin.h
index 2169a3a..7dd25bc 100644
--- a/src/nasal_builtin.h
+++ b/src/nasal_builtin.h
@@ -124,7 +124,6 @@ var builtin_coyield(var*, gc&);
 var builtin_costatus(var*, gc&);
 var builtin_corun(var*, gc&);
 var builtin_millisec(var*, gc&);
-var builtin_sysargv(var*, gc&);
 var builtin_gcextend(var*, gc&);
 var builtin_logtime(var*, gc&);
 var builtin_ghosttype(var*, gc&);
diff --git a/src/nasal_codegen.cpp b/src/nasal_codegen.cpp
index f84c53e..683fb54 100644
--- a/src/nasal_codegen.cpp
+++ b/src/nasal_codegen.cpp
@@ -211,6 +211,16 @@ void codegen::func_gen(function* node) {
     // search symbols first, must use after loading parameters
     // or the location of symbols will change and cause fatal error
     find_symbol(block);
+    // add special varibale "arg", which is used to store overflowed args
+    // but if dynamic parameter is declared, this variable will be useless
+    // for example:
+    //     var f = func(a) {print(arg)}
+    //     f(1, 2, 3);
+    // then the arg is [2, 3], because 1 is accepted by "a"
+    // so in fact "f" is the same as:
+    //     var f = func(a, arg...) {return(arg)}
+    add_symbol("arg");
+
     in_iterloop.push(0);
     block_gen(block);
     in_iterloop.pop();
@@ -1094,13 +1104,7 @@ const error& codegen::compile(parse& parse, linker& import) {
 
     // add special symbol globals, which is a hash stores all global variables
     add_symbol("globals");
-    // add special symbol arg here, which is used to store function arguments
-    // for example:
-    //     var f = func(a) {print(arg)}
-    //     f(1, 2, 3);
-    // then the arg is [2, 3], because 1 is accepted by "a"
-    // so in fact "f" is the same as:
-    //     var f = func(a, arg...) {return(arg)}
+    // add special symbol arg here, which is used to store command line args
     add_symbol("arg");
 
     find_symbol(parse.tree()); // search symbols first
diff --git a/src/nasal_lexer.cpp b/src/nasal_lexer.cpp
index a85c252..1e3d541 100644
--- a/src/nasal_lexer.cpp
+++ b/src/nasal_lexer.cpp
@@ -7,43 +7,43 @@
 #include "nasal_lexer.h"
 
 bool lexer::skip(char c) {
-    return c==' '||c=='\n'||c=='\t'||c=='\r'||c==0;
+    return c==' ' || c=='\n' || c=='\t' || c=='\r' || c==0;
 }
 
 bool lexer::is_id(char c) {
-    return (c=='_')||('a'<=c && c<='z')||('A'<=c&&c<='Z')||(c<0);   
+    return (c=='_') || ('a'<=c && c<='z') || ('A'<=c && c<='Z') || (c<0);   
 }
 
 bool lexer::is_hex(char c) {
-    return ('0'<=c&&c<='9')||('a'<=c&&c<='f')||('A'<=c && c<='F');
+    return ('0'<=c && c<='9') || ('a'<=c && c<='f') || ('A'<=c && c<='F');
 }
 
 bool lexer::is_oct(char c) {
-    return '0'<=c&&c<='7';
+    return '0'<=c && c<='7';
 }
 
 bool lexer::is_dec(char c) {
-    return '0'<=c&&c<='9';
+    return '0'<=c && c<='9';
 }
 
 bool lexer::is_str(char c) {
-    return c=='\''||c=='\"'||c=='`';
+    return c=='\'' || c=='\"' || c=='`';
 }
 
 bool lexer::is_single_opr(char c) {
     return (
-        c=='('||c==')'||c=='['||c==']'||
-        c=='{'||c=='}'||c==','||c==';'||
-        c==':'||c=='?'||c=='`'||c=='@'||
-        c=='%'||c=='$'||c=='\\'
+        c=='(' || c==')' || c=='[' || c==']' ||
+        c=='{' || c=='}' || c==',' || c==';' ||
+        c==':' || c=='?' || c=='`' || c=='@' ||
+        c=='%' || c=='$' || c=='\\'
     );
 }
 
 bool lexer::is_calc_opr(char c) {
     return (
-        c=='='||c=='+'||c=='-'||c=='*'||
-        c=='!'||c=='/'||c=='<'||c=='>'||
-        c=='~'||c=='|'||c=='&'||c=='^'
+        c=='=' || c=='+' || c=='-' || c=='*' ||
+        c=='!' || c=='/' || c=='<' || c=='>' ||
+        c=='~' || c=='|' || c=='&' || c=='^'
     );
 }
 
@@ -54,8 +54,10 @@ void lexer::skip_note() {
 
 void lexer::err_char() {
     ++column;
-    char c=res[ptr++];
-    err.err("lexer", {line, column-1, line, column, filename}, "invalid character 0x"+chrhex(c));
+    char c = res[ptr++];
+    err.err("lexer",
+        {line, column-1, line, column, filename},
+        "invalid character 0x"+chrhex(c));
     err.fatal("lexer", "fatal error occurred, stop");
 }
 
@@ -81,220 +83,241 @@ void lexer::open(const std::string& file) {
 }
 
 tok lexer::get_type(const std::string& str) {
-    return typetbl.count(str)?typetbl.at(str):tok::null;
+    return typetbl.count(str)? typetbl.at(str):tok::null;
 }
 
 std::string lexer::utf8_gen() {
-    std::string str="";
+    std::string str = "";
     while(ptr<res.size() && res[ptr]<0) {
-        std::string tmp="";
-        u32 nbytes=utf8_hdchk(res[ptr]);
+        std::string tmp = "";
+        u32 nbytes = utf8_hdchk(res[ptr]);
         if (!nbytes) {
             ++ptr;
             ++column;
             continue;
         }
 
-        tmp+=res[ptr++];
-        for(u32 i=0;i<nbytes;++i,++ptr) {
+        tmp += res[ptr++];
+        for(u32 i = 0; i<nbytes; ++i, ++ptr) {
             if (ptr<res.size() && (res[ptr]&0xc0)==0x80) {
-                tmp+=res[ptr];
+                tmp += res[ptr];
             }
         }
 
         // utf8 character's total length is 1+nbytes
         if (tmp.length()!=1+nbytes) {
             ++column;
-            std::string utf_info="0x"+chrhex(tmp[0]);
-            for(u32 i=1;i<tmp.size();++i) {
-                utf_info+=" 0x"+chrhex(tmp[i]);
+            std::string utf_info = "0x"+chrhex(tmp[0]);
+            for(u32 i = 1; i<tmp.size(); ++i) {
+                utf_info += " 0x"+chrhex(tmp[i]);
             }
-            err.err("lexer", {line, column-1, line, column, filename}, "invalid utf-8 <"+utf_info+">");
+            err.err("lexer",
+                {line, column-1, line, column, filename},
+                "invalid utf-8 <"+utf_info+">");
             err.fatal("lexer", "fatal error occurred, stop");
         }
-        str+=tmp;
-        column+=2; // may have some problems because not all the unicode takes 2 space
+        str += tmp;
+        column += 2; // may have some problems because not all the unicode takes 2 space
     }
     return str;
 }
 
 token lexer::id_gen() {
-    u32 begin_line=line;
-    u32 begin_column=column;
-    std::string str="";
+    u32 begin_line = line;
+    u32 begin_column = column;
+    std::string str = "";
     while(ptr<res.size() && (is_id(res[ptr])||is_dec(res[ptr]))) {
         if (res[ptr]<0) { // utf-8
-            str+=utf8_gen();
+            str += utf8_gen();
         } else { // ascii
-            str+=res[ptr++];
+            str += res[ptr++];
             ++column;
         }
     }
-    tok type=get_type(str);
-    return {{begin_line, begin_column, line, column, filename}, (type!=tok::null)?type:tok::id, str};
+    tok type = get_type(str);
+    return {
+        {begin_line, begin_column, line, column, filename},
+        (type!=tok::null)? type:tok::id, str};
 }
 
 token lexer::num_gen() {
-    u32 begin_line=line;
-    u32 begin_column=column;
+    u32 begin_line = line;
+    u32 begin_column = column;
     // generate hex number
     if (ptr+1<res.size() && res[ptr]=='0' && res[ptr+1]=='x') {
-        std::string str="0x";
-        ptr+=2;
+        std::string str = "0x";
+        ptr += 2;
         while(ptr<res.size() && is_hex(res[ptr])) {
-            str+=res[ptr++];
+            str += res[ptr++];
         }
-        column+=str.length();
-        if (str.length()<3) { // "0x"
-            err.err("lexer", {begin_line, begin_column, line, column, filename}, "invalid number `"+str+"`");
+        column += str.length();
+        // "0x"
+        if (str.length()<3) {
+            err.err("lexer",
+                {begin_line, begin_column, line, column, filename},
+                "invalid number `"+str+"`");
         }
         return {{begin_line, begin_column, line, column, filename}, tok::num, str};
     } else if (ptr+1<res.size() && res[ptr]=='0' && res[ptr+1]=='o') { // generate oct number
-        std::string str="0o";
-        ptr+=2;
+        std::string str = "0o";
+        ptr += 2;
         while(ptr<res.size() && is_oct(res[ptr])) {
-            str+=res[ptr++];
+            str += res[ptr++];
         }
-        bool erfmt=false;
+        bool erfmt = false;
         while(ptr<res.size() && (is_dec(res[ptr]) || is_hex(res[ptr]))) {
-            erfmt=true;
-            str+=res[ptr++];
+            erfmt = true;
+            str += res[ptr++];
         }
-        column+=str.length();
+        column += str.length();
         if (str.length()==2 || erfmt) {
-            err.err("lexer", {begin_line, begin_column, line, column, filename}, "invalid number `"+str+"`");
+            err.err("lexer",
+                {begin_line, begin_column, line, column, filename},
+                "invalid number `"+str+"`");
         }
         return {{begin_line, begin_column, line, column, filename}, tok::num, str};
     }
     // generate dec number
     // dec number -> [0~9][0~9]*(.[0~9]*)(e|E(+|-)0|[1~9][0~9]*)
-    std::string str="";
+    std::string str = "";
     while(ptr<res.size() && is_dec(res[ptr])) {
-        str+=res[ptr++];
+        str += res[ptr++];
     }
     if (ptr<res.size() && res[ptr]=='.') {
-        str+=res[ptr++];
+        str += res[ptr++];
         while(ptr<res.size() && is_dec(res[ptr])) {
-            str+=res[ptr++];
+            str += res[ptr++];
         }
         // "xxxx." is not a correct number
         if (str.back()=='.') {
-            column+=str.length();
-            err.err("lexer",{begin_line, begin_column, line, column, filename}, "invalid number `"+str+"`");
+            column += str.length();
+            err.err("lexer",
+                {begin_line, begin_column, line, column, filename},
+                "invalid number `"+str+"`");
             return {{begin_line, begin_column, line, column, filename}, tok::num, "0"};
         }
     }
     if (ptr<res.size() && (res[ptr]=='e' || res[ptr]=='E')) {
-        str+=res[ptr++];
+        str += res[ptr++];
         if (ptr<res.size() && (res[ptr]=='-' || res[ptr]=='+')) {
-            str+=res[ptr++];
+            str += res[ptr++];
         }
         while(ptr<res.size() && is_dec(res[ptr])) {
-            str+=res[ptr++];
+            str += res[ptr++];
         }
         // "xxxe(-|+)" is not a correct number
         if (str.back()=='e' || str.back()=='E' || str.back()=='-' || str.back()=='+') {
-            column+=str.length();
-            err.err("lexer",{begin_line, begin_column, line, column, filename}, "invalid number `"+str+"`");
+            column += str.length();
+            err.err("lexer",
+                {begin_line, begin_column, line, column, filename},
+                "invalid number `"+str+"`");
             return {{begin_line, begin_column, line, column, filename}, tok::num, "0"};
         }
     }
-    column+=str.length();
+    column += str.length();
     return {{begin_line, begin_column, line, column, filename}, tok::num, str};
 }
 
 token lexer::str_gen() {
-    u32 begin_line=line;
-    u32 begin_column=column;
-    std::string str="";
-    const char begin=res[ptr];
+    u32 begin_line = line;
+    u32 begin_column = column;
+    std::string str = "";
+    const char begin = res[ptr];
     ++column;
     while(++ptr<res.size() && res[ptr]!=begin) {
         ++column;
         if (res[ptr]=='\n') {
-            column=0;
+            column = 0;
             ++line;
         }
         if (res[ptr]=='\\' && ptr+1<res.size()) {
             ++column;
             ++ptr;
             switch(res[ptr]) {
-                case '0': str+='\0';    break;
-                case 'a': str+='\a';    break;
-                case 'b': str+='\b';    break;
-                case 'e': str+='\033';  break;
-                case 't': str+='\t';    break;
-                case 'n': str+='\n';    break;
-                case 'v': str+='\v';    break;
-                case 'f': str+='\f';    break;
-                case 'r': str+='\r';    break;
-                case '?': str+='\?';    break;
-                case '\\':str+='\\';    break;
-                case '\'':str+='\'';    break;
-                case '\"':str+='\"';    break;
-                default:  str+=res[ptr];break;
+                case '0': str += '\0';    break;
+                case 'a': str += '\a';    break;
+                case 'b': str += '\b';    break;
+                case 'e': str += '\033';  break;
+                case 't': str += '\t';    break;
+                case 'n': str += '\n';    break;
+                case 'v': str += '\v';    break;
+                case 'f': str += '\f';    break;
+                case 'r': str += '\r';    break;
+                case '?': str += '\?';    break;
+                case '\\':str += '\\';    break;
+                case '\'':str += '\'';    break;
+                case '\"':str += '\"';    break;
+                default:  str += res[ptr];break;
             }
             if (res[ptr]=='\n') {
-                column=0;
+                column = 0;
                 ++line;
             }
             continue;
         }
-        str+=res[ptr];
+        str += res[ptr];
     }
     // check if this string ends with a " or '
     if (ptr++>=res.size()) {
-        err.err("lexer", {begin_line, begin_column, line, column, filename}, "get EOF when generating string");
+        err.err("lexer",
+            {begin_line, begin_column, line, column, filename},
+            "get EOF when generating string");
         return {{begin_line, begin_column, line, column, filename}, tok::str, str};
     }
     ++column;
-    if (begin=='`' && str.length()!=1) {
-        err.err("lexer", {begin_line, begin_column, line, column, filename}, "\'`\' is used for string including one character");
+
+    // if is not utf8, 1+utf8_hdchk should be 1
+    if (begin=='`' && str.length()!=1+utf8_hdchk(str[0])) {
+        err.err("lexer",
+            {begin_line, begin_column, line, column, filename},
+            "\'`\' is used for string including one character");
     }
     return {{begin_line, begin_column, line, column, filename}, tok::str, str};
 }
 
 token lexer::single_opr() {
-    u32 begin_line=line;
-    u32 begin_column=column;
-    std::string str(1,res[ptr]);
+    u32 begin_line = line;
+    u32 begin_column = column;
+    std::string str(1, res[ptr]);
     ++column;
-    tok type=get_type(str);
+    tok type = get_type(str);
     if (type==tok::null) {
-        err.err("lexer", {begin_line, begin_column, line, column, filename}, "invalid operator `"+str+"`");
+        err.err("lexer",
+            {begin_line, begin_column, line, column, filename},
+            "invalid operator `"+str+"`");
     }
     ++ptr;
     return {{begin_line, begin_column, line, column, filename}, type, str};
 }
 
 token lexer::dots() {
-    u32 begin_line=line;
-    u32 begin_column=column;
-    std::string str=".";
+    u32 begin_line = line;
+    u32 begin_column = column;
+    std::string str = ".";
     if (ptr+2<res.size() && res[ptr+1]=='.' && res[ptr+2]=='.') {
-        str+="..";
+        str += "..";
     }
-    ptr+=str.length();
-    column+=str.length();
+    ptr += str.length();
+    column += str.length();
     return {{begin_line, begin_column, line, column, filename}, get_type(str), str};
 }
 
 token lexer::calc_opr() {
-    u32 begin_line=line;
-    u32 begin_column=column;
+    u32 begin_line = line;
+    u32 begin_column = column;
     // get calculation operator
-    std::string str(1,res[ptr++]);
+    std::string str(1, res[ptr++]);
     if (ptr<res.size() && res[ptr]=='=') {
-        str+=res[ptr++];
+        str += res[ptr++];
     }
-    column+=str.length();
+    column += str.length();
     return {{begin_line, begin_column, line, column, filename}, get_type(str), str};
 }
 
 const error& lexer::scan(const std::string& file) {
-    line=1;
-    column=0;
-    ptr=0;
+    line = 1;
+    column = 0;
+    ptr = 0;
     open(file);
 
     while(ptr<res.size()) {
@@ -303,7 +326,7 @@ const error& lexer::scan(const std::string& file) {
             ++column;
             if (res[ptr++]=='\n') {
                 ++line;
-                column=0;
+                column = 0;
             }
         }
         if (ptr>=res.size()) {
@@ -328,6 +351,6 @@ const error& lexer::scan(const std::string& file) {
         }
     }
     toks.push_back({{line, column, line, column, filename}, tok::eof, "<eof>"});
-    res="";
+    res = "";
     return err;
 }
diff --git a/src/nasal_misc.cpp b/src/nasal_misc.cpp
index 954ae53..4f01d0b 100644
--- a/src/nasal_misc.cpp
+++ b/src/nasal_misc.cpp
@@ -85,14 +85,14 @@ bool is_superh() {
 }
 
 f64 hex2f(const char* str) {
-    f64 ret=0;
+    f64 ret = 0;
     for(; *str; ++str) {
         if ('0'<=*str && *str<='9') {
-            ret=ret*16+(*str-'0');
+            ret = ret*16+(*str-'0');
         } else if ('a'<=*str && *str<='f') {
-            ret=ret*16+(*str-'a'+10);
+            ret = ret*16+(*str-'a'+10);
         } else if ('A'<=*str && *str<='F') {
-            ret=ret*16+(*str-'A'+10);
+            ret = ret*16+(*str-'A'+10);
         } else {
             return nan("");
         }
@@ -101,9 +101,9 @@ f64 hex2f(const char* str) {
 }
 
 f64 oct2f(const char* str) {
-    f64 ret=0;
+    f64 ret = 0;
     while('0'<=*str && *str<'8') {
-        ret=ret*8+(*str++-'0');
+        ret = ret*8+(*str++-'0');
     }
     if (*str) {
         return nan("");
@@ -118,9 +118,9 @@ f64 oct2f(const char* str) {
 // but this also makes 0.1+0.2==0.3,
 // not another result that you may get in other languages.
 f64 dec2f(const char* str) {
-    f64 ret=0,negative=1,num_pow=0;
+    f64 ret = 0, negative = 1, num_pow = 0;
     while('0'<=*str && *str<='9') {
-        ret=ret*10+(*str++-'0');
+        ret = ret*10+(*str++-'0');
     }
     if (!*str) {
         return ret;
@@ -129,10 +129,10 @@ f64 dec2f(const char* str) {
         if (!*++str) {
             return nan("");
         }
-        num_pow=0.1;
+        num_pow = 0.1;
         while('0'<=*str && *str<='9') {
-            ret+=num_pow*(*str++-'0');
-            num_pow*=0.1;
+            ret += num_pow*(*str++-'0');
+            num_pow *= 0.1;
         }
         if (!*str) {
             return ret;
@@ -145,14 +145,14 @@ f64 dec2f(const char* str) {
         return nan("");
     }
     if (*str=='-' || *str=='+') {
-        negative=(*str++=='-'? -1:1);
+        negative = (*str++=='-'? -1:1);
     }
     if (!*str) {
         return nan("");
     }
-    num_pow=0;
+    num_pow = 0;
     while('0'<=*str && *str<='9') {
-        num_pow=num_pow*10+(*str++-'0');
+        num_pow = num_pow*10+(*str++-'0');
     }
     if (*str) {
         return nan("");
@@ -161,27 +161,27 @@ f64 dec2f(const char* str) {
 }
 
 f64 str2num(const char* str) {
-    bool negative=false;
-    f64 res=0;
+    bool negative = false;
+    f64 res = 0;
     if (*str=='-' || *str=='+') {
-        negative=(*str++=='-');
+        negative = (*str++=='-');
     }
     if (!*str) {
         return nan("");
     }
     if (str[0]=='0' && str[1]=='x') {
-        res=hex2f(str+2);
+        res = hex2f(str+2);
     } else if (str[0]=='0' && str[1]=='o') {
-        res=oct2f(str+2);
+        res = oct2f(str+2);
     } else {
-        res=dec2f(str);
+        res = dec2f(str);
     }
-    return negative?-res:res;
+    return negative? -res:res;
 }
 
 i32 utf8_hdchk(const char head) {
     // RFC-2279 but now we use RFC-3629 so nbytes is less than 4
-    const u8 c=(u8)head;
+    const u8 c = (u8)head;
     if ((c>>5)==0x06) { // 110x xxxx (10xx xxxx)^1
         return 1;
     }
@@ -195,36 +195,36 @@ i32 utf8_hdchk(const char head) {
 }
 
 std::string chrhex(const char c) {
-    const char hextbl[]="0123456789abcdef";
-    return {hextbl[(c&0xf0)>>4],hextbl[c&0x0f]};
+    const char hextbl[] = "0123456789abcdef";
+    return {hextbl[(c&0xf0)>>4], hextbl[c&0x0f]};
 }
 
 std::string rawstr(const std::string& str, const usize maxlen) {
     std::string ret("");
-    for(auto i:str) {
+    for(auto i : str) {
         // windows doesn't output unicode normally, so we output the hex
         if (is_windows() && i<=0) {
-            ret+="\\x"+chrhex(i);
+            ret += "\\x"+chrhex(i);
             continue;
         }
         switch(i) {
-            case '\0':  ret+="\\0"; break;
-            case '\a':  ret+="\\a"; break;
-            case '\b':  ret+="\\b"; break;
-            case '\t':  ret+="\\t"; break;
-            case '\n':  ret+="\\n"; break;
-            case '\v':  ret+="\\v"; break;
-            case '\f':  ret+="\\f"; break;
-            case '\r':  ret+="\\r"; break;
-            case '\033':ret+="\\e"; break;
-            case '\"':  ret+="\\\"";break;
-            case '\'':  ret+="\\\'";break;
-            case '\\':  ret+="\\\\";break;
-            default:    ret+=i;     break;
+            case '\0':  ret += "\\0";  break;
+            case '\a':  ret += "\\a";  break;
+            case '\b':  ret += "\\b";  break;
+            case '\t':  ret += "\\t";  break;
+            case '\n':  ret += "\\n";  break;
+            case '\v':  ret += "\\v";  break;
+            case '\f':  ret += "\\f";  break;
+            case '\r':  ret += "\\r";  break;
+            case '\033':ret += "\\e";  break;
+            case '\"':  ret += "\\\""; break;
+            case '\'':  ret += "\\\'"; break;
+            case '\\':  ret += "\\\\"; break;
+            default:    ret += i;      break;
         }
     }
     if (maxlen && ret.length()>maxlen) {
-        ret=ret.substr(0,maxlen)+"...";
+        ret = ret.substr(0,maxlen)+"...";
     }
     return ret;
 }
\ No newline at end of file
diff --git a/src/nasal_vm.cpp b/src/nasal_vm.cpp
index 27e12e1..11057ee 100644
--- a/src/nasal_vm.cpp
+++ b/src/nasal_vm.cpp
@@ -8,26 +8,28 @@ void vm::init(
     const std::vector<std::string>& filenames,
     const std::vector<std::string>& argv
 ) {
-    cnum=nums.data();
-    cstr=strs.data();
-    bytecode=code.data();
-    files=filenames.data();
+    cnum = nums.data();
+    cstr = strs.data();
+    bytecode = code.data();
+    files = filenames.data();
 
     /* set canary and program counter */
-    ctx.pc=0;
-    ctx.localr=ctx.memr=nullptr;
-    ctx.funcr=ctx.upvalr=nil;
-    ctx.canary=stack+STACK_DEPTH-1; // stack[STACK_DEPTH-1]
-    ctx.top=stack;
-    ctx.stack=stack;
+    ctx.pc = 0;
+    ctx.localr = nullptr;
+    ctx.memr = nullptr;
+    ctx.funcr = nil;
+    ctx.upvalr = nil;
+    ctx.canary = stack+STACK_DEPTH-1; // stack[STACK_DEPTH-1]
+    ctx.top = stack;
+    ctx.stack = stack;
 
     /* clear main stack */
-    for(u32 i=0;i<STACK_DEPTH;++i) {
-        stack[i]=nil;
+    for(u32 i = 0; i<STACK_DEPTH; ++i) {
+        stack[i] = nil;
     }
 
     /* init gc */
-    ngc.init(strs,argv);
+    ngc.init(strs, argv);
 
     /* init vm globals */
     auto map_instance = ngc.alloc(vm_map);
@@ -35,10 +37,15 @@ void vm::init(
     for(const auto& i : global) {
         map_instance.map().mapper[i.first] = stack+i.second;
     }
+
+    /* init vm arg */
+    auto arg_instance = ngc.alloc(vm_vec);
+    stack[global.at("arg")] = arg_instance;
+    arg_instance.vec().elems = ngc.env_argv;
 }
 
 void vm::valinfo(var& val) {
-    const nas_val* p=val.val.gcobj;
+    const nas_val* p = val.val.gcobj;
     switch(val.type) {
         case vm_none: std::clog<<"| null |";break;
         case vm_ret:  std::clog<<"| pc   | 0x"<<std::hex
@@ -49,7 +56,8 @@ void vm::valinfo(var& val) {
         case vm_nil:  std::clog<<"| nil  |";break;
         case vm_num:  std::clog<<"| num  | "<<val.num();break;
         case vm_str:  std::clog<<"| str  | <0x"<<std::hex<<(u64)p
-                               <<"> "<<rawstr(val.str(),16)<<std::dec;break;
+                               <<"> "<<rawstr(val.str(),16)
+                               <<std::dec;break;
         case vm_func: std::clog<<"| func | <0x"<<std::hex<<(u64)p
                                <<"> entry:0x"<<val.func().entry
                                <<std::dec;break;
diff --git a/src/nasal_vm.h b/src/nasal_vm.h
index e4103e7..ac45233 100644
--- a/src/nasal_vm.h
+++ b/src/nasal_vm.h
@@ -622,9 +622,12 @@ inline void vm::o_callfv() {
         return;
     }
     auto& func = local[-1].func();
+
+    // swap funcr with local[-1]
     var tmp = local[-1];
     local[-1] = ctx.funcr;
-    ctx.funcr=tmp;
+    ctx.funcr = tmp;
+
     // top-argc+lsize(local) +1(old pc) +1(old localr) +1(old upvalr)
     if (ctx.top-argc+func.lsize+3>=ctx.canary) {
         die("stack overflow");
@@ -640,14 +643,14 @@ inline void vm::o_callfv() {
     var dynamic = nil;
     if (func.dpara>=0) { // load dynamic arguments
         dynamic = ngc.alloc(vm_vec);
-        for(u32 i=psize;i<argc;++i) {
+        for(u32 i = psize; i<argc; ++i) {
             dynamic.vec().elems.push_back(local[i]);
         }
     } else if (psize<argc) {
         // load arguments to "arg", located at stack+1
-        stack[1] = ngc.alloc(vm_vec);
-        for(u32 i=psize;i<argc;++i) {
-            stack[1].vec().elems.push_back(local[i]);
+        dynamic = ngc.alloc(vm_vec);
+        for(u32 i = psize; i<argc; ++i) {
+            dynamic.vec().elems.push_back(local[i]);
         }
     }
     // should reset stack top after allocating vector
@@ -658,22 +661,21 @@ inline void vm::o_callfv() {
     ctx.top = local+func.lsize;
 
     u32 min_size = (std::min)(psize, argc); // avoid error in MSVC
-    for(u32 i=min_size;i>=1;--i) { // load arguments
+    for(u32 i = min_size; i>=1; --i) { // load arguments
         local[i] = local[i-1];
     }
     local[0] = func.local[0];// load "me"
+
     // load local scope & default arguments
-    for(u32 i=min_size+1;i<func.lsize;++i) {
+    for(u32 i = min_size+1; i<func.lsize; ++i) {
         local[i] = func.local[i];
     }
-    if (func.dpara>=0) {
-        local[psize+1] = dynamic;
-    }
+    local[func.dpara>=0? psize+1:func.lsize-1] = dynamic;
 
     ctx.top[0] = ctx.upvalr;
     (++ctx.top)[0] = var::addr(ctx.localr);
     (++ctx.top)[0] = var::ret(ctx.pc);
-    ctx.pc=func.entry-1;
+    ctx.pc = func.entry-1;
     ctx.localr = local;
     ctx.upvalr = nil;
 }
@@ -912,9 +914,6 @@ inline void vm::o_ret() {
     ctx.funcr = ctx.top[0];
     ctx.top[0] = ret; // rewrite func with returned value
 
-    // reset "arg"
-    stack[1] = nil;
-
     if (up.type==vm_upval) { // synchronize upvalue
         auto& upval = up.upval();
         auto size = func.func().lsize;
diff --git a/std/lib.nas b/std/lib.nas
index f137fa3..e8680c3 100644
--- a/std/lib.nas
+++ b/std/lib.nas
@@ -478,7 +478,7 @@ var os = {
 # runtime gives us some functions that we could manage it manually.
 var runtime = {
     # command line arguments
-    argv: func() {return __sysargv;},
+    argv: func() {return globals.arg;},
     gc: {
         extend: func(type) {return __gcextd;}
     }
diff --git a/test/globals_test.nas b/test/globals_test.nas
index bb55d7f..c698b33 100644
--- a/test/globals_test.nas
+++ b/test/globals_test.nas
@@ -16,9 +16,12 @@ globals.test_func();
 
 var f = func() {
     println(arg);
+    func() {println(arg);}(114, 514, 1919, 810);
+    println(arg);
 }
 
 f(1, 2, 3);
 
+# command line arguments
 println(arg);
 println(globals.arg);
\ No newline at end of file
diff --git a/test/sample.nas b/test/sample.nas
index 8fb0c42..5865f17 100644
--- a/test/sample.nas
+++ b/test/sample.nas
@@ -1,16 +1,16 @@
 # This file is written by Andy Ross, and is protected by GPLv2.0
 
 # A no-op function used below to get this file to run.  Ignore and read on...
-dummyFunc = func { 1 }
+var dummyFunc = func { 1 }
 
 #
 # Literal numbers can be decimal, exponential, or hex constants.  All
 # numbers are stored internally as IEEE double-precision values.
 #
-n1 = 3;
-n2 = 3.14;
-n3 = 6.023e23;
-n3 = 0x123456;
+var n1 = 3;
+var n2 = 3.14;
+var n3 = 6.023e23;
+var n3 = 0x123456;
 
 #
 # Two identical string literals with different quotes.  Double quotes
@@ -19,14 +19,14 @@ n3 = 0x123456;
 # whitespace like newlines).  Double quotes handle the following
 # C-like escapes: \n \r \t \xnn \"
 #
-s1 = 'Andy\'s "computer" has a C:\righteous\newstuff directory.';
-s2 = "Andy's \"computer\" has a C:\\righteous\\newstuff directory.";
+var s1 = 'Andy\'s "computer" has a C:\righteous\newstuff directory.';
+var s2 = "Andy's \"computer\" has a C:\\righteous\\newstuff directory.";
 
 #
 # Literal lists use square brackets with a comma-separated expression
 # list.
 #
-list1 = ["a", "b", 1, 2];
+var list1 = ["a", "b", 1, 2];
 
 #
 # Literal hashes (or objects -- same thing) use curlies and colons to
@@ -35,8 +35,8 @@ list1 = ["a", "b", 1, 2];
 # to use symbols, lookup tables of other types will be more
 # comfortable with literals.
 #
-hash1 = { name : "Andy", job : "Hacker" };
-EnglishEspanol = { "one" : "uno", "two": "dos", "blue" : "azul" };
+var hash1 = { name : "Andy", job : "Hacker" };
+var EnglishEspanol = { "one" : "uno", "two": "dos", "blue" : "azul" };
 
 #
 # Both vectors and hashes use square brackets for the lookup operation:
@@ -50,7 +50,7 @@ hash1["name"] == "Andy";
 # (anonymous) function argument to the local "log_message" variable.
 # There is no function declaration syntax in Nasal.
 #
-log_message = func {
+var log_message = func {
     print(arg[0]);
 }
 
@@ -58,10 +58,10 @@ log_message = func {
 # You can also pass named arguments to a function, thus saving the
 # typing and performance costs of extracting them from the arg array.
 #
-sqrt = dummyFunc;
-dist = func(x1, y1, x2, y2) {
-    dx = x2-x1;
-    dy = y2-y1;
+var sqrt = dummyFunc;
+var dist = func(x1, y1, x2, y2) {
+    var dx = x2-x1;
+    var dy = y2-y1;
     return sqrt(dx*dx + dy*dy);
 }
 dist(0,0,1,1); # == sqrt(2)
@@ -71,14 +71,14 @@ dist(0,0,1,1); # == sqrt(2)
 # default value must be a scalar (number, string, function, nil) and
 # not a mutable composite object (list, hash).
 #
-read = func(bytes, flags=0) { }
+var read = func(bytes, flags=0) { }
 
 #
 # Any extra arguments after the named list are placed in the "arg"
 # vector as above.  You can rename this to something other than "arg"
 # by specifying a final argument name with an ellipsis:
 #
-listify = func(elements...) { return elements; }
+var listify = func(elements...) { return elements; }
 listify(1, 2, 3, 4); # returns a list: [1, 2, 3, 4]
 
 #
@@ -87,7 +87,7 @@ listify(1, 2, 3, 4); # returns a list: [1, 2, 3, 4]
 # good practice in general, although it is not required.  Note that
 # this is not a "declaration", just a qualifier on the "=" operator.
 #
-innerFunc = func {
+var innerFunc = func {
     for(var dist=0; dist<100; dist += 1) {
         # Does not interfere with the "dist" symbol defined above
     }
@@ -99,26 +99,26 @@ innerFunc = func {
 # what the ?: does in C.  The last semicolon in a code block is
 # optional, to make this prettier.
 #
-abs = func(n) { if(n<0) { -n } else { n } }
+var abs = func(n) { if(n<0) { -n } else { n } }
 
 #
 # But for those who don't like typing, the ternary operator works like
 # you expect:
 #
-abs = func(n) { n < 0 ? -n : n }
+var abs = func(n) { n < 0 ? -n : n }
 
 #
 # Nasal supports a "nil" value for use as a null pointer equivalent.
 # It can be tested for equality, matching only other nils.
 #
-listNode = { data : ["what", "ever"], next : nil };
+var listNode = { data : ["what", "ever"], next : nil };
 
 #
 # Nasal's binary boolean operators are "and" and "or", unlike C.
 # unary not is still "!" however.  They short-circuit like you expect
 #
-toggle = 0;
-a = nil;
+var toggle = 0;
+var a = nil;
 if(a and a.field == 42) {
     toggle = !toggle; # doesn't crash when a is nil
 }
@@ -129,24 +129,24 @@ if(a and a.field == 42) {
 # takes a local variable name as its first argument and a vector as
 # its second.
 #
-doSomething = dummyFunc;
+var doSomething = dummyFunc;
 
-stillGoing = 0;
+var stillGoing = 0;
 while(stillGoing) { doSomething(); }
 
-for(i=0; i < 3; i = i+1) {
+for(var i=0; i < 3; i = i+1) {
     elem = list1[i];
     doSomething(elem);
 }
 
-foreach(elem; list1) { doSomething(elem) }  # Shorthand for above
+foreach(var elem; list1) { doSomething(elem) }  # Shorthand for above
 
 #
 # There is also a "forindex", which is like foreach except that it
 # assigns the index of each element, instead of the value, to the loop
 # variable.
 #
-forindex(i; list1) { doSomething(list1[i]); }
+forindex(var i; list1) { doSomething(list1[i]); }
 
 #
 # Define a class object with one method, one field and one "new"
@@ -155,10 +155,10 @@ forindex(i; list1) { doSomething(list1[i]); }
 # appropriately.  Member functions can get their local object (the
 # equivalent of the "this" pointer in C++) as the "me" variable.
 #
-Class1 = {};
+var Class1 = {};
 
 Class1.new = func {
-    obj = { parents : [Class1],
+    var obj = { parents : [Class1],
             count : 0 };
     return obj;
 }
@@ -168,7 +168,7 @@ Class1.getcount = func {
     return me.count;
 }
 
-c = Class1.new();
+var c = Class1.new();
 print(c.getcount(), "\n"); # prints 1
 print(c.getcount(), "\n"); # prints 2
 print(c.getcount(), "\n"); # prints 3
@@ -177,20 +177,20 @@ print(c.getcount(), "\n"); # prints 3
 # But *set* operations always go to the local object.  You can't
 # corrupt a parent class via OOP operations on its instances (but you
 # *can* get to it via hand-inspection of the parents arrays).
-c2 = Class1.new();
-c2.getcount() = func { 12345 }; # custom "derived" function!
+var c2 = Class1.new();
+c2.getcount = func { return 12345 }; # custom "derived" function!
 
 print(c2.getcount(), "\n"); # prints 12345
-print(c1.getcount(), "\n"); # prints 4, Class1.getcount is unchanged
+print(c.getcount(), "\n"); # prints 4, Class1.getcount is unchanged
 
 #
 # This creates an identical class using alternative syntax.
 #
-Class2 = {
+var Class2 = {
     new : func {
-        obj = {};
-	obj.parents = [Class2];
-	obj.count = 0;
+        var obj = {};
+        obj.parents = [Class2];
+        obj.count = 0;
         return obj;
     },
     getcount : func {
@@ -206,7 +206,7 @@ Class2 = {
 # C (although note that there is no nul termination -- get the length
 # with size()):
 #
-string = "abcdefghijklmnopqrstuvwxyz";
+var string = "abcdefghijklmnopqrstuvwxyz";
 var ascii_sum = 0;
 for(var i=0; i<size(string); i+=1) { ascii_sum += string[i]; }
 
@@ -222,7 +222,7 @@ if(`©` != 169) { print("Unicode violation bug!\n"); }
 # can make a mutable string either with the append operator or the
 # bits.buf() function.
 #
-ascii_lc = func(string) {
+var ascii_lc = func(string) {
     var mutable = string ~ "";
     for(var i=0; i<size(mutable); i+=1) {
         if(mutable[i] >= `A` and mutable[i] <= `Z`) {
@@ -237,14 +237,14 @@ print(ascii_lc("ABCDEFG"), "\n"); # prints "abcdefg"
 # Advanced vectors: The lookup index can be negative, where -1
 # indicates the last element in the vector (or string).
 #
-next_to_last = list1[-2];
+var next_to_last = list1[-2];
 
 #
 # Remember that strings look syntactically like vectors of bytes; so
 # conversely, the "~" concatenation operator works equally well to
 # concatenate vectors:
 #
-joined_list = [1, 2, 3] ~ [4, 5, 6];
+var joined_list = [1, 2, 3] ~ [4, 5, 6];
 
 ###
 ### Now some fun examples:
@@ -254,9 +254,9 @@ joined_list = [1, 2, 3] ~ [4, 5, 6];
 # Make a "inverted index" hash out of a vector that returns the index
 # for each element.
 #
-invert = func(vec) {
-    hash = {};
-    for(i=0; i<size(vec); i = i+1) {
+var invert = func(vec) {
+    var hash = {};
+    for(var i=0; i<size(vec); i = i+1) {
         hash[vec[i]] = i;
     }
     return hash;
@@ -266,16 +266,16 @@ invert = func(vec) {
 # Use the return value of the above function to do an "index of"
 # lookup on a vector
 #
-vecfind = func(vec, elem) { return invert(vec)[elem]; }
+var vecfind = func(vec, elem) { return invert(vec)[elem]; }
 
 #
 # Joins its arguments with the empty string and returns a scalar.
 # Note use of "~" operator to do string concatenation (Nasal's only
 # funny syntax).
 #
-join = func { 
-    s = "";
-    foreach(elem; arg) { s = s ~ elem; }
+var join = func { 
+    var s = "";
+    foreach(var elem; arg) { s = s ~ elem; }
     return s;
 }
 
@@ -283,14 +283,16 @@ join = func {
 # Labeled break/continue syntax puts the label in as an extra first
 # argument to the for/while/foreach.
 #
-doneWithInnerLoopEarly = dummyFunc;
-completelyDone = dummyFunc;
-for(OUTER; i=0; i<100; i = i+1) {
-    for(j=0; j<100; j = j+1) {
+var doneWithInnerLoopEarly = dummyFunc;
+var completelyDone = dummyFunc;
+# not supported now
+for(#OUTER;
+    var i=0; i<100; i = i+1) {
+    for(var j=0; j<100; j = j+1) {
         if(doneWithInnerLoopEarly()) {
             break;
         } elsif(completelyDone()) {
-            break OUTER;
+            break #OUTER;
         }
     }
 }
@@ -303,10 +305,10 @@ for(OUTER; i=0; i<100; i = i+1) {
 ## also makes no attempt to escape special characters in strings, which
 ## can break re-parsing in strange (and possibly insecure!) ways.
 ##
-dump = func(o) {
-    result = "";
+var dump = func(o) {
+    var result = "";
     if(typeof(o) == "scalar") {
-        n = num(o);
+        var n = num(o);
         if(n == nil) { result = result ~ '"' ~ o ~ '"'; }
         else { result = result ~ o; }
     } elsif(typeof(o) == "vector") {
@@ -317,14 +319,14 @@ dump = func(o) {
         }
         result = result ~ " ]";
     } elsif(typeof(o) == "hash") {
-        ks = keys(o);
+        var ks = keys(o);
         result = result ~ "{ ";
         if(size(o) > 0) {
-            k = ks[0];
+            var k = ks[0];
             result = result ~ k ~ ":" ~ dump(o[k]);
         }
         for(i=1; i<size(o); i=i+1) {
-            k = ks[i];
+            var k = ks[i];
             result = result ~ ", " ~ k ~ " : " ~ dump(o[k]);
         }
         result = result ~ " }";
@@ -345,7 +347,7 @@ dump = func(o) {
 # normal function definition.  Oh well, every language has a syntactic
 # quirk or two...)
 #
-a = (func(n){ n + 1 })(232);  # "a" now equals 233
+var a = (func(n){ n + 1 })(232);  # "a" now equals 233
 
 #
 # Functional programming B.  All expressions have a value, the last
@@ -354,7 +356,7 @@ a = (func(n){ n + 1 })(232);  # "a" now equals 233
 # (assignment, duh) have side effects.  e.g. The "if" expression works
 # both for code flow and as the ?: expression in C/C++.
 #
-factorial = func(n) { if(n == 0) { 1 }
+var factorial = func(n) { if(n == 0) { 1 }
                       else       { n * factorial(n-1) } }
 print(factorial(10), "\n");
 
@@ -364,8 +366,8 @@ print(factorial(10), "\n");
 # local variables in the outer scope even after their creator has
 # returned.
 #
-getcounter = func { count = 0; return func { count = count + 1 } }
-mycounter = getcounter();
+var getcounter = func { var count = 0; return func { count = count + 1 } }
+var mycounter = getcounter();
 print(mycounter(), "\n"); # prints 1
 print(mycounter(), "\n"); # prints 2
 print(mycounter(), "\n"); # prints 3