Need help (inorder-preorder-postorder)

[mnf7]

My program doesn't work properly. Please help me

#include "stdafx.h"
#include <iostream>
#include <conio.h>
#include <stdio.h>
#include <string.h>
using namespace std;

class node{
	public:
		node *child_left;
		node *child_right;
		char value [11];
};
node *reshe = NULL;	
//#######################################################
void insert (node *c)
{
	node *a;
	node *b;
	b = NULL;
	a = reshe;

	while ( a!=NULL)
{
	b = a;
	if(strcmp(c->value,a->value) < 0)
{
	a= a-> child_left; 
}
	else
{
	a= a-> child_right; 
}
}
	if( b==NULL )
{
	reshe=c;
}
	else if(strcmp( c->value,b->value) < 0)
{
	b -> child_left = c;
}
	else
{
	b-> child_right = c;
}
}
//#######################################################
void preorder(node *r){
    if( r!=NULL)
	{
        cout<<"   "<< r->value;
        preorder(r->child_left);
        preorder(r->child_right);
	} 
}
//#######################################################
void inorder(node* r){
	if( r!=NULL)
	{
		inorder(r->child_left);
		cout << r->value << " " ;
		inorder(r->child_right);
	}
}
//########################################################
void postorder(node* r){
	if( r!=NULL)
	{
		inorder(r->child_left);
		inorder(r->child_right);
		cout << r->value << " " ;

	}
}
//#######################################################
void main()
{
	int choice=0 ;
	while (choice!=3){
	system("cls");
	cout<<"\n\n\t 1. Insert a Expression.";
	cout<<"\n\n\t 2. peymayesh.";
	cout<<"\n\n\t 3. Exit.";
	cout<<"\n\n\t Enter your choice : ";
	cin>>choice;

	switch (choice)
{
	case 1:{ system("cls");
			node *c=new node;
			cout<<"\n\n\t Enter your Expression Trees: ";
			cin >> c->value;
			c->child_right=NULL; 
			c->child_left=NULL; 
			insert(c); 
		   }
			break;
	case 2:{ system("cls");
			cout << "\n\n\t  peymayesh Preorder : ";
			preorder(reshe);
			cout << "\n\n\t  peymayesh Inorder : ";
			inorder(reshe);
			cout << "\n\n\t  peymayesh Postorder : ";
			postorder(reshe);
			getchar();
			getchar();
		   }
			break;
	case 3: break;
}
}
}

[weaknessforcats]

There are too many bugs in the code to address here. I suggest you step through the code using your debugger.

The obvious bugs are:
1) in the insert function the argument is a node* c. However, c is not used in the search while loop. What is used is a node* a that has never been initialized.

2)In the inorder, preorder, and postorder functions a recursive call is made if the argument node* is not NULL. However, if it is NULL, the functions just quit without doing anything.