diff --git a/version2.0/main.cpp b/version2.0/main.cpp
index 9c9d30b..c2e6931 100644
--- a/version2.0/main.cpp
+++ b/version2.0/main.cpp
@@ -1,11 +1,17 @@
 #include "nasal.h"
 
+// source code will be put in resource
 resource_file        resource;
+// source code will be generated to tokens in lexer
 nasal_lexer          lexer;
+// token list will be checked in parser and output the abstract syntax tree
 nasal_parse          parser;
+// libroot stores the ast of lib file
 abstract_syntax_tree libroot;
+// root stores the ast of source code
 abstract_syntax_tree root;
-abstract_syntax_tree linker;
+// executable_ast generates libroot and root together
+abstract_syntax_tree executable_ast;
 
 nasal_runtime runtime;
 
@@ -69,7 +75,7 @@ int main()
 			lexer.delete_all_tokens();
 			parser.delete_all_elements();
 			root.set_clear();
-			linker.set_clear();
+			executable_ast.set_clear();
 			std::cout<<">> [Delete] complete."<<std::endl;
 		}
 		else if(command=="lib")
@@ -148,11 +154,10 @@ int main()
 				parser.main_generate();
 				if(!parser.get_error())
 				{
-					linker.set_clear();
-					linker=libroot;
-					linker.merge_children(parser.get_root());
-					root=linker;
-					runtime.main_proc(root);
+					executable_ast.set_clear();
+					executable_ast=libroot;
+					executable_ast.merge_children(parser.get_root());
+					runtime.main_proc(executable_ast);
 					//root.print_tree();
 				}
 				else
diff --git a/version2.0/nasal_enum.h b/version2.0/nasal_enum.h
index d93171b..5d67f76 100644
--- a/version2.0/nasal_enum.h
+++ b/version2.0/nasal_enum.h
@@ -204,180 +204,6 @@ void print_ast_type(int type)
 	return;
 }
 
-enum parse_error_type
-{
-	parse_unknown_error=0,       // unknown error
-	error_token_in_main,         // when a token should not be the begin of a statement in main
-	error_token_in_block,        // when a token should not be the begin of a statement in block
-
-	lack_semi,
-	lack_id,
-	lack_left_curve,
-	lack_right_curve,
-	lack_right_brace,
-
-	definition_lack_id,          // lack identifier
-	definition_lack_equal,       // lack '=' when not getting ';'
-	assignment_begin_error,      // assignment begins with more than one identifier_call
-	multi_definition_need_curve, // lack right curve when generating 'var (id,id,id)'
-
-	multi_assignment_need_curve, // lack right curve when generating (scalar,scalar)=(scalar,scalar)
-	multi_assignment_need_equal, // lack '=' when generating (scalar,scalar)=(scalar,scalar)
-
-	error_begin_token_of_scalar, // in scalar_generate() 
-	
-	default_dynamic_parameter,   // default parameter should not be dynamic 
-	parameter_lack_part,         // parameter lack a ')' or identifier
-	parameter_lack_curve,        // parameter lack a ',' or ')'
-
-	special_call_func_lack_id,
-	special_call_func_lack_colon,
-	call_func_lack_comma,        // lack comma when giving parameters to a function
-	call_hash_lack_id,           // lack identifier when calling a hash
-	call_vector_wrong_comma,     // wrong use of comma like this: id[0,4:6,7,] (the last comma is incorrect here)
-	call_vector_lack_bracket,    // lack ']' when calling a vector
-	call_vector_wrong_token,     // get wrong token when calling a vector
-
-	vector_gen_lack_end,         // lack ',' or ')' when generating a vector
-	hash_gen_lack_id,            // lack identifier or string when generating a hash
-	hash_gen_lack_colon,         // lack ':' when generating a hash
-	hash_gen_lack_end,           // lack ',' or '}' when generating a hash
-
-	ternary_operator_lack_colon, // lack ':'
-};
-void print_parse_error(int error_type,int line,int error_token_type=__stack_end)
-{
-	std::string error_info_head=">> [Parse-error] line ";
-	std::string warning_info_head=">> [Parse-warning] line ";
-	switch(error_type)
-	{
-		case parse_unknown_error:
-			std::cout<<error_info_head<<line<<": unknown parse error.(token id: "<<error_token_type<<")."<<std::endl;break;
-		case error_token_in_main:
-			std::cout<<error_info_head<<line<<": statements should not begin with \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' in main scope."<<std::endl;
-			break;
-		case error_token_in_block:
-			std::cout<<error_info_head<<line<<": statements should not begin with \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' in block scope."<<std::endl;
-			break;
-		
-		case lack_semi:
-			std::cout<<error_info_head<<line<<": expect a \';\' at the end of the statement."<<std::endl;break;
-		case lack_id:
-			std::cout<<error_info_head<<line<<": expect an identifier here."<<std::endl;break;
-		case lack_left_curve:
-			std::cout<<error_info_head<<line<<": expect a \'(\' here."<<std::endl;break;
-		case lack_right_curve:
-			std::cout<<error_info_head<<line<<": expect a \')\' here."<<std::endl;break;
-		case lack_right_brace:
-			std::cout<<error_info_head<<line<<": expect a \'}\' here."<<std::endl;break;
-		
-		case definition_lack_id:
-			std::cout<<error_info_head<<line<<": expect identifier(s) after \'var\'."<<std::endl;break;
-		case definition_lack_equal:
-			std::cout<<error_info_head<<line<<": expect a \'=\' here but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' when generating definition."<<std::endl;
-			break;
-		case assignment_begin_error:
-			std::cout<<error_info_head<<line<<": assignment should begin with one identifier_call."<<std::endl;
-			break;
-		case multi_definition_need_curve:
-			std::cout<<error_info_head<<line<<": expect a \')\' here but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' ."<<std::endl;
-			break;
-		
-		case multi_assignment_need_curve:
-			std::cout<<error_info_head<<line<<": expect a \')\' here but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' ."<<std::endl;
-			break;
-		case multi_assignment_need_equal:
-			std::cout<<error_info_head<<line<<": expect a \'=\' here but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' ."<<std::endl;
-			break;
-		
-		case error_begin_token_of_scalar:
-			std::cout<<error_info_head<<line<<": expect a scalar here but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' ."<<std::endl;
-			break;
-		
-		case default_dynamic_parameter:
-			std::cout<<error_info_head<<line<<": dynamic parameter should not have a default value."<<std::endl;break;
-		case parameter_lack_part:
-			std::cout<<error_info_head<<line<<": expect a \')\' or identifier here when generating parameter_list."<<std::endl;break;
-		case parameter_lack_curve:
-			std::cout<<error_info_head<<line<<": expect a \')\' or \',\' here when generating parameter_list."<<std::endl;break;
-		
-		case special_call_func_lack_id:
-			std::cout<<error_info_head<<line<<": expect an identifier here but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' when calling functions."<<std::endl;
-			break;
-		case special_call_func_lack_colon:
-			std::cout<<error_info_head<<line<<": expect an \':\' here but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' when calling functions."<<std::endl;
-			break;
-		case call_func_lack_comma:
-			std::cout<<error_info_head<<line<<": expect a \',\' when calling a function but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' ."<<std::endl;
-			break;
-		case call_hash_lack_id:
-			std::cout<<error_info_head<<line<<": expect an identifier after \'.\' ."<<std::endl;break;
-		case call_vector_wrong_comma:
-			std::cout<<error_info_head<<line<<": expect a scalar after \',\' but get \']\' ."<<std::endl;
-			break;
-		case call_vector_lack_bracket:
-			std::cout<<error_info_head<<line<<": expect a \']\' here but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' ."<<std::endl;
-			break;
-		case call_vector_wrong_token:
-			std::cout<<error_info_head<<line<<": expect \':\' or ',' or ']' here but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' ."<<std::endl;
-			break;
-		
-		case vector_gen_lack_end:
-			std::cout<<error_info_head<<line<<": expect a \',\' or \')\' here but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' ."<<std::endl;
-			break;
-		case hash_gen_lack_id:
-			std::cout<<error_info_head<<line<<": expect an identifier or string here but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' ."<<std::endl;
-			break;
-		case hash_gen_lack_colon:
-			std::cout<<error_info_head<<line<<": expect a \':\' here but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' ."<<std::endl;
-			break;
-		case hash_gen_lack_end:
-			std::cout<<error_info_head<<line<<": expect a \',\' or \'}\' here but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' ."<<std::endl;
-			break;
-		
-		case ternary_operator_lack_colon:
-			std::cout<<error_info_head<<line<<": expect a \':\' here but get \'";
-			print_parse_token(error_token_type);
-			std::cout<<"\' ."<<std::endl;
-			break;
-		default:
-			std::cout<<error_info_head<<line<<": unknown parse error.(token id: "<<error_token_type<<")."<<std::endl;break;
-	}
-	return;
-}
-
 enum scalar_type
 {
 	scalar_nil=0,
diff --git a/version2.0/nasal_gc.h b/version2.0/nasal_gc.h
index 4165378..5fd6134 100644
--- a/version2.0/nasal_gc.h
+++ b/version2.0/nasal_gc.h
@@ -12,6 +12,7 @@ class nasal_function
 {
 	private:
 		std::list<std::map<std::string,int> > local_scope;
+		abstract_syntax_tree parameter_list;
 		abstract_syntax_tree function_root;
 		// parent_hash_addr is used to store the address of the hash which has this nasal_function
 		// because nasal_function needs this address to adjust the identifier called 'me' in local_scope
@@ -19,8 +20,10 @@ class nasal_function
 	public:
 		void set_clear();
 		void set_local_scope(std::list<std::map<std::string,int> >&);
+		void set_paramemter_list(abstract_syntax_tree&);
 		void set_statement_block(abstract_syntax_tree&);
 		std::list<std::map<std::string,int> >& get_local_scope();
+		abstract_syntax_tree& get_parameter_list();
 		abstract_syntax_tree& get_statement_block();
 		void deep_copy(nasal_function&);
 };
@@ -255,6 +258,11 @@ void nasal_function::set_local_scope(std::list<std::map<std::string,int> >& tmp_
 				nasal_gc.reference_add(i->second);
 	return;
 }
+void nasal_function::set_paramemter_list(abstract_syntax_tree& para_list)
+{
+	parameter_list=para_list;
+	return;
+}
 void nasal_function::set_statement_block(abstract_syntax_tree& func_block)
 {
 	function_root=func_block;
@@ -264,6 +272,10 @@ std::list<std::map<std::string,int> >& nasal_function::get_local_scope()
 {
 	return local_scope;
 }
+abstract_syntax_tree& nasal_function::get_parameter_list()
+{
+	return parameter_list;
+}
 abstract_syntax_tree& nasal_function::get_statement_block()
 {
 	return function_root;
@@ -282,6 +294,7 @@ void nasal_function::deep_copy(nasal_function& tmp)
 		for(std::map<std::string,int>::iterator i=iter->begin();i!=iter->end();++i)
 				nasal_gc.reference_add(i->second);
 	// copy abstract_syntax_tree
+	parameter_list=tmp.parameter_list;
 	function_root=tmp.function_root;
 	return;
 }
@@ -342,7 +355,11 @@ void nasal_vector::vec_push(int addr)
 }
 int nasal_vector::get_elem(int addr)
 {
-	if(0<=addr && addr<nas_array.size())
+	// 0 ~ size-1 -size ~ -1
+	int bound=nas_array.size();
+	if(-bound<=addr && addr<0)
+		return nas_array[bound+addr];
+	else if(0<=addr && addr<bound)
 		return nas_array[addr];
 	return -1;
 }
diff --git a/version2.0/nasal_parse.h b/version2.0/nasal_parse.h
index fb1c7f5..e1b73f7 100644
--- a/version2.0/nasal_parse.h
+++ b/version2.0/nasal_parse.h
@@ -7,27 +7,64 @@ class nasal_parse
 		std::stack<token> parse_token_stream;
 		std::stack<token> checked_tokens;
 		token this_token;
-		int error;
+		int   error;
 		abstract_syntax_tree root;
+		enum parse_error_type
+		{
+			parse_unknown_error=0,       // unknown error
+			error_token_in_main,         // when a token should not be the begin of a statement in main
+			error_token_in_block,        // when a token should not be the begin of a statement in block
 
+			lack_semi,
+			lack_id,
+			lack_left_curve,
+			lack_right_curve,
+			lack_right_brace,
+
+			definition_lack_id,          // lack identifier
+			definition_lack_equal,       // lack '=' when not getting ';'
+			assignment_begin_error,      // assignment begins with more than one identifier_call
+			multi_definition_need_curve, // lack right curve when generating 'var (id,id,id)'
+
+			multi_assignment_need_curve, // lack right curve when generating (scalar,scalar)=(scalar,scalar)
+			multi_assignment_need_equal, // lack '=' when generating (scalar,scalar)=(scalar,scalar)
+
+			error_begin_token_of_scalar, // in scalar_generate() 
+			
+			default_dynamic_parameter,   // default parameter should not be dynamic 
+			parameter_lack_part,         // parameter lack a ')' or identifier
+			parameter_lack_curve,        // parameter lack a ',' or ')'
+
+			special_call_func_lack_id,
+			special_call_func_lack_colon,
+			call_func_lack_comma,        // lack comma when giving parameters to a function
+			call_hash_lack_id,           // lack identifier when calling a hash
+			call_vector_wrong_comma,     // wrong use of comma like this: id[0,4:6,7,] (the last comma is incorrect here)
+			call_vector_lack_bracket,    // lack ']' when calling a vector
+			call_vector_wrong_token,     // get wrong token when calling a vector
+
+			vector_gen_lack_end,         // lack ',' or ')' when generating a vector
+			hash_gen_lack_id,            // lack identifier or string when generating a hash
+			hash_gen_lack_colon,         // lack ':' when generating a hash
+			hash_gen_lack_end,           // lack ',' or '}' when generating a hash
+
+			ternary_operator_lack_colon, // lack ':'
+		};
+		void print_parse_error(int,int,int);
 		// most important function of parser
 		// these two functions are used to get and push token
 		// by using them,parser can generate ast
 		void get_token();
 		void push_token();
-
 		// block statements generation
 		abstract_syntax_tree block_generate();
-
 		// check ';'
 		void check_semi();
-
 		// check '(' confliction
 		bool check_multi_assignment();// check multi_call_id '=' multi_scalar
 		bool check_multi_scalar();    // check multi_scalar
 		bool check_var_in_curve();    // check multi_definition: (var id,id,id)
 		bool check_function_end(abstract_syntax_tree&);    // check end of definition or '=' is a function
-
 		/*
 		calculation() will get elements generated by and_calculation()
 		and_calculation() will get elements generated by or_calculation()
@@ -48,14 +85,13 @@ class nasal_parse
 		abstract_syntax_tree additive_calculation();
 		abstract_syntax_tree multive_calculation();
 		abstract_syntax_tree scalar_generate();
-
 		// normal data type generation
 		abstract_syntax_tree hash_generate();
 		abstract_syntax_tree vector_generate();
 		abstract_syntax_tree function_generate();
-
 		// return_expr() generates ebnf: <return> [<calculation>] ';'
 		abstract_syntax_tree return_expr();
+		// normal expressions
 		abstract_syntax_tree multi_scalar_assignment();
 		abstract_syntax_tree definition();
 		abstract_syntax_tree loop_expr();
@@ -74,9 +110,8 @@ class nasal_parse
 		}
 		void print_detail_token();
 		void get_token_list(std::list<token>&);
-		int get_error();
+		int  get_error();
 		abstract_syntax_tree& get_root();
-		
 		// abstract_syntax_tree generation
 		// main process of parser
 		void main_generate();
@@ -114,6 +149,8 @@ void nasal_parse::print_detail_token()
 
 void nasal_parse::get_token_list(std::list<token>& detail_token_stream)
 {
+	// get detail_token_stream from lexer
+	// clear the parse_token_stream and checked_tokens list
 	while(!parse_token_stream.empty())
 		parse_token_stream.pop();
 	while(!checked_tokens.empty())
@@ -142,6 +179,130 @@ void nasal_parse::get_token_list(std::list<token>& detail_token_stream)
 	return;
 }
 
+void nasal_parse::print_parse_error(int error_type,int line,int error_token_type=__stack_end)
+{
+	std::string error_info_head=">> [Parse] line ";
+	switch(error_type)
+	{
+		case parse_unknown_error:
+			std::cout<<error_info_head<<line<<": unknown parse error.(token id: "<<error_token_type<<")."<<std::endl;break;
+		case error_token_in_main:
+			std::cout<<error_info_head<<line<<": statements should not begin with \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' in main scope."<<std::endl;
+			break;
+		case error_token_in_block:
+			std::cout<<error_info_head<<line<<": statements should not begin with \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' in block scope."<<std::endl;
+			break;
+		case lack_semi:
+			std::cout<<error_info_head<<line<<": expect a \';\' at the end of the statement."<<std::endl;break;
+		case lack_id:
+			std::cout<<error_info_head<<line<<": expect an identifier here."<<std::endl;break;
+		case lack_left_curve:
+			std::cout<<error_info_head<<line<<": expect a \'(\' here."<<std::endl;break;
+		case lack_right_curve:
+			std::cout<<error_info_head<<line<<": expect a \')\' here."<<std::endl;break;
+		case lack_right_brace:
+			std::cout<<error_info_head<<line<<": expect a \'}\' here."<<std::endl;break;
+		case definition_lack_id:
+			std::cout<<error_info_head<<line<<": expect identifier(s) after \'var\'."<<std::endl;break;
+		case definition_lack_equal:
+			std::cout<<error_info_head<<line<<": expect a \'=\' here but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' when generating definition."<<std::endl;
+			break;
+		case assignment_begin_error:
+			std::cout<<error_info_head<<line<<": assignment should begin with one identifier_call."<<std::endl;
+			break;
+		case multi_definition_need_curve:
+			std::cout<<error_info_head<<line<<": expect a \')\' here but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' ."<<std::endl;
+			break;
+		case multi_assignment_need_curve:
+			std::cout<<error_info_head<<line<<": expect a \')\' here but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' ."<<std::endl;
+			break;
+		case multi_assignment_need_equal:
+			std::cout<<error_info_head<<line<<": expect a \'=\' here but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' ."<<std::endl;
+			break;
+		case error_begin_token_of_scalar:
+			std::cout<<error_info_head<<line<<": expect a scalar here but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' ."<<std::endl;
+			break;
+		case default_dynamic_parameter:
+			std::cout<<error_info_head<<line<<": dynamic parameter should not have a default value."<<std::endl;break;
+		case parameter_lack_part:
+			std::cout<<error_info_head<<line<<": expect a \')\' or identifier here when generating parameter_list."<<std::endl;break;
+		case parameter_lack_curve:
+			std::cout<<error_info_head<<line<<": expect a \')\' or \',\' here when generating parameter_list."<<std::endl;break;
+		case special_call_func_lack_id:
+			std::cout<<error_info_head<<line<<": expect an identifier here but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' when calling functions."<<std::endl;
+			break;
+		case special_call_func_lack_colon:
+			std::cout<<error_info_head<<line<<": expect an \':\' here but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' when calling functions."<<std::endl;
+			break;
+		case call_func_lack_comma:
+			std::cout<<error_info_head<<line<<": expect a \',\' when calling a function but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' ."<<std::endl;
+			break;
+		case call_hash_lack_id:
+			std::cout<<error_info_head<<line<<": expect an identifier after \'.\' ."<<std::endl;break;
+		case call_vector_wrong_comma:
+			std::cout<<error_info_head<<line<<": expect a scalar after \',\' but get \']\' ."<<std::endl;
+			break;
+		case call_vector_lack_bracket:
+			std::cout<<error_info_head<<line<<": expect a \']\' here but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' ."<<std::endl;
+			break;
+		case call_vector_wrong_token:
+			std::cout<<error_info_head<<line<<": expect \':\' or ',' or ']' here but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' ."<<std::endl;
+			break;
+		case vector_gen_lack_end:
+			std::cout<<error_info_head<<line<<": expect a \',\' or \')\' here but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' ."<<std::endl;
+			break;
+		case hash_gen_lack_id:
+			std::cout<<error_info_head<<line<<": expect an identifier or string here but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' ."<<std::endl;
+			break;
+		case hash_gen_lack_colon:
+			std::cout<<error_info_head<<line<<": expect a \':\' here but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' ."<<std::endl;
+			break;
+		case hash_gen_lack_end:
+			std::cout<<error_info_head<<line<<": expect a \',\' or \'}\' here but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' ."<<std::endl;
+			break;
+		case ternary_operator_lack_colon:
+			std::cout<<error_info_head<<line<<": expect a \':\' here but get \'";
+			print_parse_token(error_token_type);
+			std::cout<<"\' ."<<std::endl;
+			break;
+		default:
+			std::cout<<error_info_head<<line<<": unknown parse error.(token id: "<<error_token_type<<")."<<std::endl;break;
+	}
+	return;
+}
+
 void nasal_parse::get_token()
 {
 	if(!parse_token_stream.empty())
diff --git a/version2.0/nasal_runtime.h b/version2.0/nasal_runtime.h
index 0c3df25..cbf068a 100644
--- a/version2.0/nasal_runtime.h
+++ b/version2.0/nasal_runtime.h
@@ -41,7 +41,7 @@ class nasal_runtime
         void definition         (std::list<std::map<std::string,int> >&,std::map<std::string,int>&,abstract_syntax_tree&);
         void loop_expr          (std::list<std::map<std::string,int> >&,abstract_syntax_tree&);
         void conditional        (std::list<std::map<std::string,int> >&,abstract_syntax_tree&);
-        int  func_proc          (std::list<std::map<std::string,int> >&,abstract_syntax_tree&);
+        int  func_proc          (std::list<std::map<std::string,int> >&,abstract_syntax_tree&,abstract_syntax_tree&);
     public:
         nasal_runtime()
         {
@@ -203,11 +203,18 @@ int nasal_runtime::function_generation(std::list<std::map<std::string,int> >& lo
     nasal_gc.get_scalar(addr).set_type(scalar_function);
     nasal_gc.get_scalar(addr).get_function().set_local_scope(local_scope);
     // function
-    //  parameters
-    //  block
-    //  calls...
+    //     parameters
+    //     block
+    //     calls...
     std::list<abstract_syntax_tree>::iterator i=node.get_children().begin();
-
+    nasal_gc.get_scalar(addr).get_function().set_paramemter_list(*i);
+    ++i;
+    nasal_gc.get_scalar(addr).get_function().set_statement_block(*i);
+    ++i;
+    for(;i!=node.get_children().end();++i)
+    {
+        ;
+    }
     return addr;
 }
 int nasal_runtime::calculation(std::list<std::map<std::string,int> >& local_scope,abstract_syntax_tree& node)
@@ -1114,6 +1121,7 @@ int nasal_runtime::call_identifier(std::list<std::map<std::string,int> >& local_
             }
             else if(called_type==scalar_hash)
             {
+                
                 if(nasal_gc.get_scalar(data_addr).get_type()!=scalar_string)
                 {
                     error_interrupt(__error_value_type,iter->get_node_line());
@@ -1351,7 +1359,7 @@ void nasal_runtime::conditional(std::list<std::map<std::string,int> >& local_sco
     return;
 }
 
-int nasal_runtime::func_proc(std::list<std::map<std::string,int> >& local_scope,abstract_syntax_tree& func_root)
+int nasal_runtime::func_proc(std::list<std::map<std::string,int> >& local_scope,abstract_syntax_tree& parameter_list,abstract_syntax_tree& func_root)
 {
     if(func_root.get_node_type()!=__function)
     {
@@ -1361,12 +1369,12 @@ int nasal_runtime::func_proc(std::list<std::map<std::string,int> >& local_scope,
     std::map<std::string,int> new_scope;
     local_scope.push_back(new_scope);
     // loading parameters
-    for(std::list<abstract_syntax_tree>::iterator iter=func_root.get_children().front().get_children().begin();iter!=func_root.get_children().front().get_children().end();++iter)
+    for(std::list<abstract_syntax_tree>::iterator iter=parameter_list.get_children().begin();iter!=parameter_list.get_children().end();++iter)
     {
 
     }
     // process
-    for(std::list<abstract_syntax_tree>::iterator iter=func_root.get_children().back().get_children().begin();iter!=func_root.get_children().back().get_children().end();++iter)
+    for(std::list<abstract_syntax_tree>::iterator iter=func_root.get_children().begin();iter!=func_root.get_children().end();++iter)
     {
         // use local value node_type to avoid calling function too many times.
         int node_type=iter->get_node_type();