C program to implement queue operations

#include<stdio.h>
#include<conio.h>
#define max 5
int q[10],front=0,rear=-1;
void main()
{
int ch;
void insert();
void delet();
void display();
clrscr();
printf("\nQueue operations\n");
printf("1.insert\n2.delete\n3.display\n4.exit\n");
while(1)
{
printf("Enter your choice:");
scanf("%d",&ch);
switch(ch)
{
case 1: insert();
break;
case 2: delet();
break;
case 3:display();
break;
case 4:exit();
default:printf("Invalid option\n");
}
}
}
 
void insert()
{
int x;
if(rear==max-1)
printf("Queue is overflow\n");
else
{
printf("Enter element to be insert:");
scanf("%d",&x);
q[++rear]=x;
}
}
void  delet()
{
int a;
if((front==0)&&(rear==-1))
{
printf("Queue is underflow\n");
getch();
exit();
}
a=q[front++];
printf("Deleted element is:%d\n",a);
if(front>rear)
{
front=0;
rear=-1;
}
}
 
void display()
{
int i;
if(front==0&&rear==-1)
{
printf("Queue is underflow\n");
getch();
exit();
}
for(i=front;i<=rear;i++)
printf("\t%d",q[i]);
printf("\n");
}
getch();