diff --git a/nasal_hash.cpp b/nasal_hash.cpp
index f048ee2..83fb8dc 100644
--- a/nasal_hash.cpp
+++ b/nasal_hash.cpp
@@ -445,5 +445,36 @@ NasalHash& NasalHash::operator=(const NasalHash &Source)
 	return *this;
 }
 
+void NasalHash::SearchElement(std::string &ElementName)
+{
+	HashUnit *temp=head;
+	while(temp->next)
+	{
+		temp=temp->next;
+		if(temp->VarName==ElementName)
+		{
+			if(temp->Type=="int")
+				std::cout<<*((int *)temp->data);
+			else if(temp->Type=="float")
+				std::cout<<*((float *)temp->data);
+			else if(temp->Type=="double")
+				std::cout<<*((double *)temp->data);
+			else if(temp->Type=="char")
+				std::cout<<*((char *)temp->data);
+			else if(temp->Type=="long long int")
+				std::cout<<*((long long int *)temp->data);
+			else if(temp->Type=="string")
+				std::cout<<*((std::string *)temp->data);
+			else if(temp->Type=="array")
+				((NasalList *)temp->data)->PrintList();
+			else if(temp->Type=="hash")
+				((NasalHash *)temp->data)->PrintHash();
+			return;
+		}
+	}
+	std::cout<<"[Error] Could not find \""<<ElementName<<"\""<<std::endl;
+	return;
+}
+
 }
 #endif
diff --git a/nasal_hash.h b/nasal_hash.h
index e60cbba..a2e74d1 100644
--- a/nasal_hash.h
+++ b/nasal_hash.h
@@ -33,6 +33,7 @@ class NasalHash
 		NasalList Keys();
 		void Delete(const char *);
 		NasalHash& operator=(const NasalHash&);
+		void SearchElement(std::string &);
 };
 
 }
diff --git a/nasal_list.cpp b/nasal_list.cpp
index 820f1f6..42a8903 100644
--- a/nasal_list.cpp
+++ b/nasal_list.cpp
@@ -819,6 +819,27 @@ NasalList NasalList::Sort(const int SortType,const int _cmp)
 	return TempList;
 }
 
+void NasalList::SearchElement(const int n)
+{
+	if(n<0)
+	{
+		std::cout<<"[Error] "<<n<<" is less than 0."<<std::endl;
+	}
+	ListUnit *temp=head;
+	int cnt=-1;
+	while(temp->next)
+	{
+		temp=temp->next;
+		cnt++;
+		if(cnt==n)
+		{
+			return;
+		}
+	}
+	std::cout<<"[Error] Out of range: real end: "<<cnt<<", less than "<<n<<"."<<std::endl;
+	return;
+}
+
 var::var(var &p)
 {
 	Type=p.Type;
@@ -965,7 +986,7 @@ void var::Print()
 	else if(Type=="long long int")
 		std::cout<<*((long long int *)data);
 	else if(Type=="string")
-		std::cout<<*((std::string *)data);
+		std::cout<<"\""<<*((std::string *)data)<<"\"";
 	else if(Type=="array")
 		(*((NasalList *)data)).PrintList();
 	else if(Type=="hash")
diff --git a/nasal_list.h b/nasal_list.h
index bc2ef3b..a7ba586 100644
--- a/nasal_list.h
+++ b/nasal_list.h
@@ -36,6 +36,7 @@ class NasalList
 		NasalList SubVec(const int,const int);
 		var Pop();
 		NasalList Sort(const int,const int);
+		void SearchElement(const int);
 };
 
 class var
diff --git a/process_stack.h b/process_stack.h
index 5c14f97..a8960f8 100644
--- a/process_stack.h
+++ b/process_stack.h
@@ -10,9 +10,9 @@ namespace nasal
 
 struct process_stack_unit
 {
-	int line;           //place the unit first appear
-	std::string Name;//content of the unit or name of the var/class/function
-	std::string type;   //var class function
+	int line;                  //place the unit first appear
+	std::string name;          //content of the unit or name of the var/class/function
+	std::string format_type;   //var class function string info
 	var unitdata;
 	bool global;
 	process_stack_unit *next;
@@ -29,9 +29,9 @@ class process_stack
 		{
 			head=new process_stack_unit;
 			head->line=0;
-			head->Name="InterpreterInfo";
+			head->name="InterpreterInfo";
+			head->format_type="Info";
 			head->global=false;
-			head->type="information";
 			head->unitdata.Type="string";
 			head->unitdata.data=new std::string;
 			*((std::string *)head->unitdata.data)="# Nasal language for FlightGear.";
@@ -68,9 +68,9 @@ class process_stack
 			last_node->next=temp;
 			temp->next=NULL;
 			
-			temp->Name=p.Name;
+			temp->name=p.name;
 			temp->line=p.line;
-			temp->type=p.type;
+			temp->format_type=p.format_type;
 			temp->global=p.global;
 			temp->unitdata=p.unitdata;
 			
@@ -80,28 +80,57 @@ class process_stack
 		{
 			process_stack_unit *temp=head;
 			std::cout<<"In stack: "<<std::endl;
-			std::cout<<temp->line<<": |"<<temp->type<<"| \""<<temp->Name<<"\""<<std::endl;
-			while(temp->next)
-			{
-				temp=temp->next;
-				std::cout<<temp->line<<": |"<<temp->type<<"| \""<<temp->Name<<"\""<<std::endl;
-			}
 			if(reverse_mode_used)
+			{
+				while(temp->next)
+					temp=temp->next;
 				while(temp->last)
 				{
-					std::cout<<temp->line<<": |"<<temp->type<<"| \""<<temp->Name<<"\""<<std::endl;
+					std::cout<<"line "<<temp->line<<": |"<<temp->format_type<<"|"<<temp->name<<"|\n\t|";
+					temp->unitdata.Print();
+					std::cout<<std::endl;
 					temp=temp->last;
 				}
+				std::cout<<"line "<<temp->line<<": |"<<temp->format_type<<"|"<<temp->name<<"|\n\t|";
+				temp->unitdata.Print();
+				std::cout<<std::endl;
+			}
+			else
+			{
+				std::cout<<"line "<<temp->line<<": |"<<temp->format_type<<"|"<<temp->name<<"|\n\t|";
+				temp->unitdata.Print();
+				std::cout<<std::endl;
+				while(temp->next)
+				{
+					temp=temp->next;
+					std::cout<<"line "<<temp->line<<": |"<<temp->format_type<<"|"<<temp->name<<"|\n\t|";
+					temp->unitdata.Print();
+					std::cout<<std::endl;
+				}
+			}
 			std::cout<<"End."<<std::endl;
 			return;
 		}
+		void pop()
+		{
+			process_stack_unit *temp=head;
+			process_stack_unit *last_node;
+			while(temp->next)
+			{
+				last_node=temp;
+				temp=temp->next;
+			}
+			last_node->next=NULL;
+			delete temp;
+			return;
+		}
 		bool check_stack(std::string &ElementName)
 		{
 			process_stack_unit *temp=head;
 			while(temp->next)
 			{
 				temp=temp->next;
-				if(temp->Name==ElementName)
+				if(temp->name==ElementName)
 					return true;
 			}
 			return false;
@@ -112,7 +141,7 @@ class process_stack
 			while(temp->next)
 			{
 				temp=temp->next;
-				if(temp->Name==ElementName)
+				if(temp->name==ElementName)
 				{
 					temp->unitdata.Print();
 					return;