Queue operation insert delete and display|Studyinight Programmer

#include<stdio.h>
#define MAX 5
int q[30],front=0,rear=-1;
void main()
{
    int ch;
    void insert();
    void delet();
    void display();
    printf("1.insert\n2.delete\n3.display\n4.exit\n");
    while(1)
    {
    printf("enter your choice\n");
    scanf("%d",&ch);
    switch(ch)
    {
      case 1:insert();
      break;
      case 2:delet();
      break;
      case 3:display();
      break;
      case 4:exit(1);
      break;
      default:printf("you select wrong choice\n");

    }
}
}
void insert()
{
    if(rear==MAX-1)
        printf("your queue is full you cant insert\n");
    else
    {
        int n;
        printf("\nenter your element you want to insert\n");
        scanf("%d",&n)
;

        q[rear+1]=n;
        rear++;
    }
}
void delet()
{
    if(front==rear+1)
        printf("queue is empty delete is not possible\n ");
        else
        {
            int y; y=q[front];
            front=front+1;
            printf("deleted element is %d\n",y);
            if(front>rear)
            {
                front=0;
                rear=-1;
            }
        }
}
void display()
{
    int i ;
    if(front==rear+1)
        printf("queue is empty\n");
    else
    {
        for(i=front;i<=rear;i++)
        {
            printf("%d\t",q[i]);
        }
        printf("\n");
    }
}