problem in free up the memory

#include "stdafx.h"
#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
#include<malloc.h>
#include<stdlib.h>
#include<ctype.h>  //include the necessary header files
struct queue
{
	int data;
	queue*next;	   //Declare the structure for queue
}*front=NULL,*rear=NULL,*temp;//create the pointer for the queue stack
int enqueue(int);
int display();
void deletelement();
void intialize();	//Initialize the functions
int main(int argc, char* argv[])
{		
	int choice;
	int element;
		
	while(1)
	{
	printf("\nEnter the choice \n1-Enqueue\n2-Display\n3-Dequeue\n4-Initialize\n5-Exit\n");
	scanf("%d",&choice);//Get the choice from the user
	
//	temp=new queue();
	//temp1=(queue*)malloc(sizeof(struct queue));
	switch(choice)
	{

	case 1:
		printf("Enter the data to be insert in to the queue");
		scanf("%d",&element);
	/*	if(isalpha(element))	//Get the element from the user
			{
				printf("Sorry you enter the wrong input");
			}
		else*/
		enqueue(element);		//Invoke the enqueue function
		break;
	case 2:
		display();				//Invoke the display function
		break;
	case 3:
		deletelement();			//Invoke the delete function
		break;
	case 4:
		intialize();
		break;
	case 5:
		exit(0);

	}

	}
		return 0;
}
int enqueue(int insertelement)
{

	temp=(queue*)malloc(sizeof(struct queue)*1024);
//realloc(temp,sizeof(queue));
	temp->data=insertelement;
	temp->next=NULL;
	if(front==NULL)
	{
		front=temp;
	}
	else
		rear->next=temp;
	rear=temp;
	//free(temp);
	return 0;
}
int display()
{
	
	temp=(queue*)malloc(sizeof(struct queue)*1024);
	//realloc(temp,sizeof(queue));
	temp=front;
	printf("i am ready\n");
	while(temp!=NULL)
	{
		printf("%d\t",temp->data);
		temp=temp->next;
	}
		free(temp);
	return 0;
}
void deletelement()
{
	temp=front;
	if(temp!=NULL)
	{
		front=front->next;
		free(temp);
	}
	else
		printf("\n The queue is already empty\n The Delete opearation can't be performed\n");
}

void intialize()
{
	
		//front=NULL;
		//rear=NULL;
		free(temp);
		
		free(front);
		
		free(rear);
		printf("\nThe queue has been reintialized\n");
		
		printf("hai");

}</ctype.h></stdlib.h></malloc.h></stdlib.h></conio.h></stdio.h>