diff --git a/README.md b/README.md
index 74ff242..b11feb9 100644
--- a/README.md
+++ b/README.md
@@ -105,7 +105,7 @@ If you think `-O3` isn't that safe and stable, you could choose:
 >
 > mingw32-make stable-release-mingw
 
-You could create project in `Visual Studio` by this way: [CLICK](./doc/vs.md).
+You could create project in `Visual Studio` by this way: [__CLICK__](./doc/vs.md).
 
 ## __How to Use__
 
@@ -679,7 +679,7 @@ Then we write a test nasal file to run this fib function, using `os.platform()`
 
 ```javascript
 import("lib.nas");
-var dlhandle=dylib.dlopen("./module/libfib."~(os.platform()=="windows"?"dll":"so"));
+var dlhandle=dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
 var fib=dylib.dlsym(dlhandle,"fib");
 for(var i=1;i<30;i+=1)
     println(dylib.dlcall(fib,i));
diff --git a/doc/README_zh.md b/doc/README_zh.md
index f5fa575..57d2f48 100644
--- a/doc/README_zh.md
+++ b/doc/README_zh.md
@@ -92,7 +92,7 @@ __`linux/macOS/Unix`__ 平台直接使用make即可:
 >
 > mingw32-make stable-release-mingw
 
-你可以在`Visual Studio`中用这种方式来创建项目：[点击跳转](../doc/vs.md)。
+你可以在`Visual Studio`中用这种方式来创建项目：[__点击跳转__](../doc/vs.md)。
 
 ## __使用方法__
 
@@ -643,7 +643,7 @@ Windows(`.dll`):
 
 ```javascript
 import("lib.nas");
-var dlhandle=dylib.dlopen("./module/libfib."~(os.platform()=="windows"?"dll":"so"));
+var dlhandle=dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
 var fib=dylib.dlsym(dlhandle,"fib");
 for(var i=1;i<30;i+=1)
     println(dylib.dlcall(fib,i));
diff --git a/lib.nas b/lib.nas
index a850a15..8621639 100644
--- a/lib.nas
+++ b/lib.nas
@@ -427,16 +427,18 @@ var dylib=
 {
     # open dynamic lib.
     dlopen:  func(libname){
+        # find dynamic lib from local dir first
+        if(io.exists(libname))
+            return __dlopen(libname);
+        # find dynamic lib through PATH
         var envpath=split(os.platform()=="windows"?";":":",unix.getenv("PATH"));
-        var path=os.platform()=="windows"?["\\","\\module\\"]:["/","/module/"];
+        # first find ./module
+        append(envpath,".");
+        var path=os.platform()=="windows"?"\\module\\":"/module/";
         foreach(var p;envpath){
-            p=[p~path[0]~libname,p~path[1]~libname];
-            if(io.exists(p[0])){
-                libname=p[0];
-                break;
-            }
-            if(io.exists(p[1])){
-                libname=p[1];
+            p~=path~libname;
+            if(io.exists(p)){
+                libname=p;
                 break;
             }
         }
diff --git a/main.cpp b/main.cpp
index 203dc05..edb4914 100644
--- a/main.cpp
+++ b/main.cpp
@@ -24,26 +24,23 @@ void help()
     <<"option:\n"
     <<"    -h, --help      | get this help.\n"
     <<"    -v, --version   | get version of nasal interpreter.\n\n"
-    <<"nasal <file>\n"
-    <<"file:\n"
-    <<"    input file name to execute script file.\n\n"
     <<"nasal [option...] <file> [argv...]\n"
     <<"option:\n"
     <<"    -l,   --lex     | view token info.\n"
     <<"    -a,   --ast     | view abstract syntax tree.\n"
     <<"    -c,   --code    | view bytecode.\n"
     <<"    -e,   --exec    | execute.\n"
-    <<"    -t,   --time    | execute and get the running time.\n"
-    <<"    -o,   --opcnt   | execute and count used operands.\n"
-    <<"                    | this options is available in debug mode.\n"
-    <<"    -d,   --detail  | execute and get detail crash info.\n"
+    <<"    -t,   --time    | get the running time.\n"
+    <<"    -o,   --opcnt   | count used operands.\n"
+    <<"                    | available in debug mode.\n"
+    <<"    -d,   --detail  | get detail crash info.\n"
     <<"                    | get garbage collector info if didn't crash.\n"
     <<"    -op,  --optimize| use optimizer(beta).\n"
     <<"                    | if want to use -op and run, please use -op -e/-t/-d.\n"
     <<"    -dbg, --debug   | debug mode (this will ignore -t -d).\n"
     <<"    -cp,  --chkpath | show path if linker cannot find files.\n"
     <<"file:\n"
-    <<"    input file name to execute script file.\n"
+    <<"    input file name to execute.\n"
     <<"argv:\n"
     <<"    command line arguments used in program.\n";
 }
diff --git a/module/libfib.nas b/module/libfib.nas
index f9a576e..07f6d63 100644
--- a/module/libfib.nas
+++ b/module/libfib.nas
@@ -1,5 +1,5 @@
 var libfib=func(){
-    var dl=dylib.dlopen("./module/libfib."~(os.platform()=="windows"?"dll":"so"));
+    var dl=dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
     var fib=dylib.dlsym(dl,"fib");
     var qfib=dylib.dlsym(dl,"quick_fib");
     var call=dylib.dlcall;
diff --git a/module/libkey.nas b/module/libkey.nas
index 2b11735..114799a 100644
--- a/module/libkey.nas
+++ b/module/libkey.nas
@@ -1,5 +1,5 @@
 var libkey=func(){
-    var lib=dylib.dlopen("./module/libkey"~(os.platform()=="windows"?".dll":".so"));
+    var lib=dylib.dlopen("libkey"~(os.platform()=="windows"?".dll":".so"));
     var kb=dylib.dlsym(lib,"nas_kbhit");
     var gt=dylib.dlsym(lib,"nas_getch");
     var nb=dylib.dlsym(lib,"nas_noblock");
diff --git a/module/libsock.nas b/module/libsock.nas
index c7fb8df..e187fce 100644
--- a/module/libsock.nas
+++ b/module/libsock.nas
@@ -1,5 +1,5 @@
 var socket=func(){
-    var lib=dylib.dlopen("./module/libnasock"~(os.platform()=="windows"?".dll":".so"));
+    var lib=dylib.dlopen("libnasock"~(os.platform()=="windows"?".dll":".so"));
     var sock=dylib.dlsym(lib,"nas_socket");
     var closesocket=dylib.dlsym(lib,"nas_closesocket");
     var shutdown=dylib.dlsym(lib,"nas_shutdown");
diff --git a/nasal_ast.h b/nasal_ast.h
index 3529a4c..19aab06 100644
--- a/nasal_ast.h
+++ b/nasal_ast.h
@@ -214,12 +214,9 @@ void nasal_ast::print(int depth,bool last=false)
     for(auto& i:intentation)
         std::cout<<i;
     std::cout<<ast_name[_type];
-    if(
-        _type==ast_str ||
-        _type==ast_id ||
-        _type==ast_default ||
-        _type==ast_dynamic ||
-        _type==ast_callh)
+    if(_type==ast_str || _type==ast_id ||
+       _type==ast_default || _type==ast_dynamic ||
+       _type==ast_callh)
         std::cout<<":"<<rawstr(_str);
     else if(_type==ast_num || _type==ast_file)
         std::cout<<":"<<_num;
diff --git a/nasal_import.h b/nasal_import.h
index cba47da..1b38c41 100644
--- a/nasal_import.h
+++ b/nasal_import.h
@@ -64,24 +64,24 @@ string nasal_import::path(const nasal_ast& node)
 
 string nasal_import::findf(const string& fname)
 {
-#ifdef _WIN32
-    std::vector<string> filepath={fname,"stl\\"+fname};
-#else
-    std::vector<string> filepath={fname,"stl/"+fname};
-#endif
+    std::vector<string> filepath={fname};
     for(auto&p:envpath)
     {
 #ifdef _WIN32
         filepath.push_back(p+"\\"+fname);
-        filepath.push_back(p+"\\stl\\"+fname);
 #else
         filepath.push_back(p+"/"+fname);
-        filepath.push_back(p+"/stl/"+fname);
 #endif
     }
     for(auto& i:filepath)
         if(access(i.c_str(),F_OK)!=-1)
             return i;
+    if(fname=="lib.nas")
+#ifdef _WIN32
+        return findf("stl\\lib.nas");
+#else
+        return findf("stl/lib.nas");
+#endif
     if(!show_path)
     {
         nerr.err("link","cannot find file <"+fname+">");
diff --git a/stl/lib.nas b/stl/lib.nas
index a850a15..8621639 100644
--- a/stl/lib.nas
+++ b/stl/lib.nas
@@ -427,16 +427,18 @@ var dylib=
 {
     # open dynamic lib.
     dlopen:  func(libname){
+        # find dynamic lib from local dir first
+        if(io.exists(libname))
+            return __dlopen(libname);
+        # find dynamic lib through PATH
         var envpath=split(os.platform()=="windows"?";":":",unix.getenv("PATH"));
-        var path=os.platform()=="windows"?["\\","\\module\\"]:["/","/module/"];
+        # first find ./module
+        append(envpath,".");
+        var path=os.platform()=="windows"?"\\module\\":"/module/";
         foreach(var p;envpath){
-            p=[p~path[0]~libname,p~path[1]~libname];
-            if(io.exists(p[0])){
-                libname=p[0];
-                break;
-            }
-            if(io.exists(p[1])){
-                libname=p[1];
+            p~=path~libname;
+            if(io.exists(p)){
+                libname=p;
                 break;
             }
         }
diff --git a/test/module_test.nas b/test/module_test.nas
index ea11ab7..7f87809 100644
--- a/test/module_test.nas
+++ b/test/module_test.nas
@@ -3,7 +3,7 @@ var libfib=func(){
     return {
         open:func(){
             if(dd==nil){
-                dd=dylib.dlopen("./module/libfib."~(os.platform()=="windows"?"dll":"so"));
+                dd=dylib.dlopen("libfib."~(os.platform()=="windows"?"dll":"so"));
                 fib=dylib.dlsym(dd,"fib");
                 qfib=dylib.dlsym(dd,"quick_fib");
             }else{
diff --git a/test/occupation.nas b/test/occupation.nas
index 6c5d38a..59c6131 100644
--- a/test/occupation.nas
+++ b/test/occupation.nas
@@ -18,7 +18,7 @@ var cpu_stat=func(){
 }
 var cpu_occupation=func(){
     var cpu0=cpu_stat();
-    unix.sleep(1);
+    unix.sleep(0.5);
     var cpu1=cpu_stat();
     var t0=cpu0.user+cpu0.nice+cpu0.system+cpu0.idle+cpu0.iowait+cpu0.irq+cpu0.softirq;
     var t1=cpu1.user+cpu1.nice+cpu1.system+cpu1.idle+cpu1.iowait+cpu1.irq+cpu1.softirq;