diff --git a/version3.0/lib.nas b/version3.0/lib.nas
index c0d63d9..62af564 100644
--- a/version3.0/lib.nas
+++ b/version3.0/lib.nas
@@ -27,6 +27,32 @@ var sleep=func(duration)
     nasal_call_builtin_sleep(duration);
     return;
 }
+
+var split=func(delimeter,string)
+{
+    return nasal_call_builtin_split(delimeter,string);
+}
+var rand=func(seed=nil)
+{
+    return nasal_call_builtin_rand(seed);
+}
+var id=func(thing)
+{
+    return nasal_call_builtin_get_id(thing);
+}
+var int=func(value)
+{
+    return nasal_call_builtin_trans_int(value);
+}
+var num=func(value)
+{
+    return nasal_call_builtin_trans_num(value);
+}
+var pop=func(vector)
+{
+    return nasal_call_builtin_pop_back(vector);
+}
+
 var io=
 {
     fin:func(filename)
diff --git a/version3.0/nasal.h b/version3.0/nasal.h
index 71212c2..49a46c8 100644
--- a/version3.0/nasal.h
+++ b/version3.0/nasal.h
@@ -1,8 +1,7 @@
 #ifndef __NASAL_H__
 #define __NASAL_H__
 
-
-
+#include <unistd.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <iostream>
diff --git a/version3.0/nasal_builtin.h b/version3.0/nasal_builtin.h
index a7e55c4..b1eac64 100644
--- a/version3.0/nasal_builtin.h
+++ b/version3.0/nasal_builtin.h
@@ -119,7 +119,11 @@ int nasal_runtime::builtin_setsize(int local_scope_addr)
     int vec_size=ref_vector.size();
     if(number<vec_size)
         for(int i=number;i<vec_size;++i)
-            ref_vector.del_elem(number);
+        {
+            int addr=ref_vector.del_elem();
+            if(addr>=0)
+                nasal_vm.del_reference(addr);
+        }
     else if(number>vec_size)
         for(int i=vec_size;i<number;++i)
         {
@@ -192,7 +196,7 @@ int nasal_runtime::builtin_sleep(int local_scope_addr)
     }
     else
         sleep_time=(unsigned long)nasal_vm.gc_get(value_addr).get_number();
-    _sleep(sleep_time);
+    sleep(sleep_time); // sleep in unistd.h will make this progress sleep sleep_time seconds.
     int ret_addr=nasal_vm.gc_alloc();
     nasal_vm.gc_get(ret_addr).set_type(vm_nil);
     return ret_addr;
@@ -258,4 +262,171 @@ int nasal_runtime::builtin_foutput(int local_scope_addr)
     return ret_addr;
 }
 
+
+int nasal_runtime::builtin_split(int local_scope_addr)
+{
+    int delimeter_value_addr=-1;
+    if(local_scope_addr>=0)
+        delimeter_value_addr=nasal_vm.gc_get(local_scope_addr).get_closure().get_value_address("delimeter");
+    if(delimeter_value_addr<0 || nasal_vm.gc_get(delimeter_value_addr).get_type()!=vm_string)
+    {
+        std::cout<<">> [runtime] builtin_split: cannot find values or wrong value type(must be string)."<<std::endl;
+        ++error;
+        return -1;
+    }
+    int string_value_addr=-1;
+    if(local_scope_addr>=0)
+        string_value_addr=nasal_vm.gc_get(local_scope_addr).get_closure().get_value_address("string");
+    if(string_value_addr<0 || nasal_vm.gc_get(string_value_addr).get_type()!=vm_string)
+    {
+        std::cout<<">> [runtime] builtin_split: cannot find values or wrong value type(must be string)."<<std::endl;
+        ++error;
+        return -1;
+    }
+    std::string delimeter=nasal_vm.gc_get(delimeter_value_addr).get_string();
+    std::string source=nasal_vm.gc_get(string_value_addr).get_string();
+    int delimeter_len=delimeter.length();
+    if(delimeter_len<1)
+    {
+        std::cout<<">> [runtime] builtin_split: delimeter's length must be greater than 0."<<std::endl;
+        ++error;
+        return -1;
+    }
+    int source_len=source.length();
+
+    int ret_addr=nasal_vm.gc_alloc();
+    nasal_vm.gc_get(ret_addr).set_type(vm_vector);
+    nasal_vector& ref_vec=nasal_vm.gc_get(ret_addr).get_vector();
+    std::string tmp="";
+    for(int i=0;i<source_len;++i)
+    {
+        bool check_delimeter=false;
+        if(source[i]==delimeter[0])
+            for(int j=0;j<delimeter_len;++j)
+            {
+                if(i+j>=source_len || source[i+j]!=delimeter[j])
+                    break;
+                if(j==delimeter_len-1)
+                    check_delimeter=true;
+            }
+        if(check_delimeter)
+        {
+            int str_addr=nasal_vm.gc_alloc();
+            nasal_vm.gc_get(str_addr).set_type(vm_string);
+            nasal_vm.gc_get(str_addr).set_string(tmp);
+            ref_vec.add_elem(str_addr);
+            tmp="";
+            i+=delimeter_len-1;
+        }
+        else
+            tmp+=source[i];
+    }
+    if(tmp.length())
+    {
+        int str_addr=nasal_vm.gc_alloc();
+        nasal_vm.gc_get(str_addr).set_type(vm_string);
+        nasal_vm.gc_get(str_addr).set_string(tmp);
+        ref_vec.add_elem(str_addr);
+        tmp="";
+    }
+    return ret_addr;
+}
+int nasal_runtime::builtin_rand(int local_scope_addr)
+{
+    int value_addr=-1;
+    if(local_scope_addr>=0)
+        value_addr=nasal_vm.gc_get(local_scope_addr).get_closure().get_value_address("seed");
+    if(value_addr<0 || (nasal_vm.gc_get(value_addr).get_type()!=vm_number && nasal_vm.gc_get(value_addr).get_type()!=vm_nil))
+    {
+        std::cout<<">> [runtime] builtin_rand: cannot find values or wrong value type(must be nil or number)."<<std::endl;
+        ++error;
+        return -1;
+    }
+    if(nasal_vm.gc_get(value_addr).get_type()==vm_number)
+    {
+        unsigned int number=(unsigned int)nasal_vm.gc_get(value_addr).get_number();
+        srand(number);
+        int ret_addr=nasal_vm.gc_alloc();
+        nasal_vm.gc_get(ret_addr).set_type(vm_nil);
+        return ret_addr;
+    }
+    double num=0;
+    for(int i=0;i<5;++i)
+        num=(num+rand())*(1.0/(RAND_MAX+1.0));
+    int ret_addr=nasal_vm.gc_alloc();
+    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    nasal_vm.gc_get(ret_addr).set_number(num);
+    return ret_addr;
+}
+int nasal_runtime::builtin_id(int local_scope_addr)
+{
+    int value_addr=-1;
+    if(local_scope_addr>=0)
+        value_addr=nasal_vm.gc_get(local_scope_addr).get_closure().get_value_address("id");
+    if(value_addr<0)
+    {
+        std::cout<<">> [runtime] builtin_id: cannot find this value."<<std::endl;
+        ++error;
+        return -1;
+    }
+    int ret_addr=nasal_vm.gc_alloc();
+    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    nasal_vm.gc_get(ret_addr).set_number((double)value_addr);
+    return ret_addr;
+}
+int nasal_runtime::builtin_int(int local_scope_addr)
+{
+    int value_addr=-1;
+    if(local_scope_addr>=0)
+        value_addr=nasal_vm.gc_get(local_scope_addr).get_closure().get_value_address("value");
+    if(value_addr<0 || nasal_vm.gc_get(value_addr).get_type()!=vm_number)
+    {
+        std::cout<<">> [runtime] builtin_int: cannot find this value or wrong value type(must be number)."<<std::endl;
+        ++error;
+        return -1;
+    }
+    int number=(int)nasal_vm.gc_get(value_addr).get_number();
+    int ret_addr=nasal_vm.gc_alloc();
+    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    nasal_vm.gc_get(ret_addr).set_number((double)number);
+    return ret_addr;
+}
+int nasal_runtime::builtin_num(int local_scope_addr)
+{
+    int value_addr=-1;
+    if(local_scope_addr>=0)
+        value_addr=nasal_vm.gc_get(local_scope_addr).get_closure().get_value_address("value");
+    if(value_addr<0 || nasal_vm.gc_get(value_addr).get_type()!=vm_string)
+    {
+        std::cout<<">> [runtime] builtin_num: cannot find this value or wrong value type(must be string)."<<std::endl;
+        ++error;
+        return -1;
+    }
+    std::string str=nasal_vm.gc_get(value_addr).get_string();
+    if(!check_numerable_string(str))
+    {
+        std::cout<<">> [runtime] builtin_num: this is not a numerable string."<<std::endl;
+        ++error;
+        return -1;
+    }
+    double number=trans_string_to_number(str);
+    int ret_addr=nasal_vm.gc_alloc();
+    nasal_vm.gc_get(ret_addr).set_type(vm_number);
+    nasal_vm.gc_get(ret_addr).set_number(number);
+    return ret_addr;
+}
+int nasal_runtime::builtin_pop(int local_scope_addr)
+{
+    int value_addr=-1;
+    if(local_scope_addr>=0)
+        value_addr=nasal_vm.gc_get(local_scope_addr).get_closure().get_value_address("vector");
+    if(value_addr<0 || nasal_vm.gc_get(value_addr).get_type()!=vm_vector)
+    {
+        std::cout<<">> [runtime] builtin_pop: cannot find this value or wrong value type(must be vector)."<<std::endl;
+        ++error;
+        return -1;
+    }
+    int ret_addr=nasal_vm.gc_get(value_addr).get_vector().del_elem();
+    return -1;
+}
 #endif
\ No newline at end of file
diff --git a/version3.0/nasal_gc.h b/version3.0/nasal_gc.h
index 51326bb..8ff46d3 100644
--- a/version3.0/nasal_gc.h
+++ b/version3.0/nasal_gc.h
@@ -21,7 +21,7 @@ public:
     nasal_vector();
     ~nasal_vector();
     void add_elem(int);
-    int  del_elem(int);
+    int  del_elem();
     int  size();
     int  get_value_address(int);
     int  get_mem_address(int);
@@ -186,14 +186,14 @@ void nasal_vector::add_elem(int value_address)
     elems.push_back(memory_address);
     return;
 }
-int nasal_vector::del_elem(int index)
+int nasal_vector::del_elem()
 {
-    if(index>=elems.size())
+    // pop back
+    if(!elems.size())
         return -1;
-    int ret=elems[index];
-    nasal_vm.mem_free(ret);
-    for(int i=index;i<elems.size()-1;++i)
-        elems[i]=elems[i+1];
+    int ret=nasal_vm.mem_get(elems.back());
+    nasal_vm.add_reference(ret);
+    nasal_vm.mem_free(elems.back());
     elems.pop_back();
     return ret;
 }
diff --git a/version3.0/nasal_runtime.h b/version3.0/nasal_runtime.h
index dc446e0..73cd031 100644
--- a/version3.0/nasal_runtime.h
+++ b/version3.0/nasal_runtime.h
@@ -10,7 +10,7 @@ enum runtime_returned_state
     rt_exit_without_error
 };
 
-#define BUILTIN_FUNC_NUM 8
+#define BUILTIN_FUNC_NUM 14
 std::string builtin_func_name[BUILTIN_FUNC_NUM]=
 {
     "nasal_call_builtin_std_cout",
@@ -20,7 +20,13 @@ std::string builtin_func_name[BUILTIN_FUNC_NUM]=
     "nasal_call_builtin_input",
     "nasal_call_builtin_sleep",
     "nasal_call_builtin_finput",
-    "nasal_call_builtin_foutput"
+    "nasal_call_builtin_foutput",
+    "nasal_call_builtin_split",
+    "nasal_call_builtin_rand",
+    "nasal_call_builtin_get_id",
+    "nasal_call_builtin_trans_int",
+    "nasal_call_builtin_trans_num",
+    "nasal_call_builtin_pop_back"
 };
 
 class nasal_runtime
@@ -87,6 +93,12 @@ private:
     int builtin_sleep(int);
     int builtin_finput(int);
     int builtin_foutput(int);
+    int builtin_split(int);
+    int builtin_rand(int);
+    int builtin_id(int);
+    int builtin_int(int);
+    int builtin_num(int);
+    int builtin_pop(int);
 public:
     nasal_runtime();
     ~nasal_runtime();
@@ -558,24 +570,30 @@ int nasal_runtime::conditional_progress(nasal_ast& node,int local_scope_addr,boo
 int nasal_runtime::call_scalar(nasal_ast& node,int local_scope_addr)
 {
     int value_address=-1;
-    std::string val_name=node.get_children()[0].get_str();
-    if(local_scope_addr>=0)
-        value_address=nasal_vm.gc_get(local_scope_addr).get_closure().get_value_address(val_name);
-    if(value_address<0)
-        value_address=nasal_vm.gc_get(global_scope_address).get_closure().get_value_address(val_name);
-    if(value_address<0)
+    std::string val_name="";
+    if(node.get_children()[0].get_type()==ast_identifier)
     {
-        value_address=call_builtin_function(node.get_children()[0],local_scope_addr);
-        if(value_address>=0)
-            return value_address;
+        val_name=node.get_children()[0].get_str();
+        if(local_scope_addr>=0)
+            value_address=nasal_vm.gc_get(local_scope_addr).get_closure().get_value_address(val_name);
+        if(value_address<0)
+            value_address=nasal_vm.gc_get(global_scope_address).get_closure().get_value_address(val_name);
+        if(value_address<0)
+        {
+            value_address=call_builtin_function(node.get_children()[0],local_scope_addr);
+            if(value_address>=0)
+                return value_address;
+        }
+        if(value_address<0)
+        {
+            std::cout<<">> [runtime] call_nasal_scalar: cannot find value named \'"<<val_name<<"\'."<<std::endl;
+            ++error;
+            return -1;
+        }
+        nasal_vm.add_reference(value_address);
     }
-    if(value_address<0)
-    {
-        std::cout<<">> [runtime] call_nasal_scalar: cannot find value named \'"<<val_name<<"\'."<<std::endl;
-        ++error;
-        return -1;
-    }
-    nasal_vm.add_reference(value_address);
+    else
+        value_address=calculation(node.get_children()[0],local_scope_addr);
     int call_expr_size=node.get_children().size();
     int last_call_hash_addr=-1;
     for(int i=1;i<call_expr_size;++i)
@@ -1059,17 +1077,17 @@ int nasal_runtime::call_function(nasal_ast& node,std::string func_name,int base_
 int nasal_runtime::call_builtin_function(nasal_ast& node,int local_scope_addr)
 {
     int ret_value_addr=-1;
-    int builtin_num=-1;
+    int builtin_func_num=-1;
     std::string builtin_name=node.get_str();
     for(int i=0;i<BUILTIN_FUNC_NUM;++i)
         if(builtin_name==builtin_func_name[i])
         {
-            builtin_num=i;
+            builtin_func_num=i;
             break;
         }
-    if(builtin_num<0)
+    if(builtin_func_num<0)
         return -1;
-    switch(builtin_num)
+    switch(builtin_func_num)
     {
         case 0:ret_value_addr=builtin_print(local_scope_addr);break;
         case 1:ret_value_addr=builtin_append(local_scope_addr);break;
@@ -1079,6 +1097,12 @@ int nasal_runtime::call_builtin_function(nasal_ast& node,int local_scope_addr)
         case 5:ret_value_addr=builtin_sleep(local_scope_addr);break;
         case 6:ret_value_addr=builtin_finput(local_scope_addr);break;
         case 7:ret_value_addr=builtin_foutput(local_scope_addr);break;
+        case 8:ret_value_addr=builtin_split(local_scope_addr);break;
+        case 9:ret_value_addr=builtin_rand(local_scope_addr);break;
+        case 10:ret_value_addr=builtin_id(local_scope_addr);break;
+        case 11:ret_value_addr=builtin_int(local_scope_addr);break;
+        case 12:ret_value_addr=builtin_num(local_scope_addr);break;
+        case 13:ret_value_addr=builtin_pop(local_scope_addr);break;
     }
     return ret_value_addr;
 }