Basic Priority queue in C

The source code of basic priority queue is given :

#include<stdio.h>
#include<malloc.h>

void insert();
void del();
void display();



struct node
    {

        int priority;
        int info;
        struct node *next;
    }*start, *q, *temp, *new;

typedef struct node *N;

int main()
{
    int ch;

    do
     {
            printf( "\n[1] INSERTION\t[2] DELETION\t[3] DISPLAY [4] EXIT\t:" );
            scanf( "%d", &ch );

            switch ( ch )
                {
                case 1:
                    insert();
                    break;
                case 2:
                    del();
                    break;
                case 3:
                    display();
                    break;
                case 4:
                    break;
                }
        }

    while ( ch < 4 );
}



void insert()
{

    int item, itprio;
    new = ( N* ) malloc( sizeof( N ) );

    printf( "ENTER THE ELT.TO BE INSERTED :\t" );
    scanf( "%d", &item );
    printf( "ENTER ITS PRIORITY :\t" );
    scanf( "%d", &itprio );
    new->info = item;
    new->priority = itprio;

    if ( start == NULL || itprio < start->priority )
    {
        new->next = start;
        start = new;
    }
    else
        {
            q = start;
            while ( q->next != NULL && q->next->priority <= itprio )
                q = q->next;

            new->next = q->next;
            q->next = new;
        }
}

void del()
{
    if ( start == NULL )
    {
         printf( "\nQUEUE UNDERFLOW\n" );
    }
    else
    {
    new = start;
    printf( "\nDELETED ITEM IS %d\n", new->info );
    start = start->next;
    free( start );

    }

}

void display()
{
    temp = start;
    if ( start == NULL )
        printf( "QUEUE IS EMPTY\n" );

    else
    {
        printf( "QUEUE IS:\n" );

        while ( temp != NULL )
        {
            printf( "\t%d[priority=%d]", temp->info, temp->priority );
            temp = temp->next;
        }
     }
}