Circular queue using array

#include<stdio.h>
#include<conio.h>
#define size 5

int queue[size],rear=-1,front=-1,item;
void insert();
void delet();
void display();

void main() {
 int choice;
 clrscr();
 do {
  printf("\n1.Insert\n2.Delete\n3.Display\n4.Exit\nChoose one: ");
  scanf("%d",&choice);
  switch(choice) {
   case 1: insert(); break;
   case 2: delet(); break;
   case 3: display(); break;
   case 4: break;
   default: printf("Invalid choice.\n");
  }
 } while(choice!=4);
}

void insert() {
 if((front==0 && rear==size-1) || front==rear+1)
  printf("Queue is full.\n");
 else {
  printf("\nEnter the element: ");
  scanf("%d",&item);
  if(rear==-1) {
   rear=0;
   front=0;
  } else if(rear==size-1)
   rear=0;
  else
   rear++;
  queue[rear]=item;
  printf("Item inserted: %d\n",item);
 }
}

void delet() {
 if(front==-1)
  printf("Queue is empty.\n");
 else {
  item=queue[front];
  if(front==rear) {
   front=-1;
   rear=-1;
  } else if(front==size-1)
   front=0;
  else
   front++;
  printf("Element deleted: %d\n",item);
 }
}

void display() {
 int i;
 if(front==-1)
  printf("Queue is empty.\n");
 else if(front>rear) {
  for(i=front;i<=size;i++) {
   printf("%d\t",queue[i]);
  }
  for(i=0;i<=rear;i++) {
   printf("%d\t",queue[i]);
  }
 } else {
  for(i=front;i<=rear;i++) {
   printf("%d\t",queue[i]);
  }
 }
}