Data Structure C program Queue using Linked List Dev c++

 #include <stdio.h>  
 struct queue{  
       int data;  
       struct queue* next;  
       };  
       typedef struct queue* node;  
       node front=NULL,rear=NULL;  
       /* declaration of function */  
       void display();  
       void enqueue(node);  
       int dequeue();  
 void enqueue(node x)  
 {  
    if(front==NULL)//for inserting first element  
    {  
     rear=x;  
     front=x;  
     rear->next=NULL;//IMP  
    }  
    else//general case  
    {  
      rear->next=x;  
      rear=x;  
      rear->next=NULL;  
    }  
 }  
 int dequeue()  
 {  
   int x;  
   if(front==NULL)//if empty  
   {  
    printf("Empty queue\n");  
    return;  
    }  
    else//if not empty  
    {  
      node temp=front;  
      x=temp->data;  
      front=front->next;  
      free(temp);   
    }  
    if(front==NULL)//if deleted the last element  
    {  
     rear=NULL;  
    }  
    return x;  
 }  
 void display()  
 {  
    if(front==NULL)  
    {  
    printf("Queue Empty\n");  
    return;  
    }  
    node temp=front;  
    printf("Queue is:-\n");  
    while(temp!=NULL)  
    {  
     printf("%d\n",temp->data);  
     temp=temp->next;  
    }  
 }  
 int main()  
 {  
   int ch;  
   printf("1.Enqueue\n2.Dequeue\n3.Display\n4.Exit\n");  
   scanf("%d",&ch);  
   node temp;  
   int x;  
   while(ch!=4)  
   {  
    switch(ch)  
    {  
     case 1:  
         temp=(struct queue*)malloc(sizeof(struct queue));  
         printf("Enter data:");  
         scanf("%d",&(*temp).data);  
         enqueue(temp);  
         break;  
     case 2:  
         x=dequeue();  
         printf("Removed %d\n",x);  
         break;  
     case 3:  
         display();  
         break;  
     default:printf("WRONG CHOICE ENTER AGAIN\n");  
    }  
    printf("1.Enqueue\n2.Dequeue\n3.Display\n4.Exit\n");  
    scanf("%d",&ch);  
   }  
 }