C Program of Simple Queue

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
void main()
{
    int queue[10],front=1,rear=1,ch,val,i;
clrscr();
do{
printf("\n 1.add 2.delete 3.display 4.exit");
scanf("%d",& ch);
if(ch == 1)
 {
   scanf("%d",& val);
if(front == -1 && rear == -1)
{
  front =0;
  rear =0;
  queue[rear]=val;
}
else
if(rear<9)
 {
   queue[++rear]=val;
 }
else
 printf("queue is full");
 }
if(ch == 2)
 {
   if(front<=rear)
{
  printf("%d",queue[front++]);
}
else
printf("queue is empty");
 }
if(ch == 3)
 {
   for(i=front;i<=rear;i++)
printf("%d",queue[i]);
 }
if(ch == 4)
 exit(0);
    }while(1)
     getch();


}