wap to implement  queue

#include<stdio.h>
#include<conio.h>
#define MAX 30
struct queue
{
int a[MAX];
int front,rear;
}q;
void main()
{
int i,op,x;
q.rear=-1;
q.front=-1;
clrscr();
do
{
printf("\nmain menu:");
printf("\n1)enqueuen\n2)dequeue\n3)display\n4)exit");
printf("\nenter your choioce");
scanf("%d",&op);
switch(op)
{
case 1: if(q.rear==MAX-1)
printf("\nqueue is full");
else
{
printf("\nenter element");
scanf("%d",&x);
if(q.rear==-1)
{
q.rear=q.rear+1;
q.front=q.front+1;
q.a[q.rear]=x;
}
else
{
q.rear=q.rear+1;
q.a[q.rear]=x;
}
}
break;
case 2: if(q.rear==-1)
printf("\n wueue is empty");
else
{
if(q.rear==q.front)
{
x=q.a[q.front];
q.front=-1;
q.rear=-1;
printf("\ndeleted element is:%d",x);
}
else
{
x=q.a[q.front];
q.front=q.front+1;
printf("\ndeleted element is %d",x);
}
}
break;
case 3: if(q.rear==-1)
printf("\nqueue is empty");
else
{
printf("\nqueue is");
for(i=q.front;i<=q.rear;i++)
printf("<%d>",q.a[i]);
}
break;
}
}while(op!=4);
getch();
}