Insertion in priority queue not working when the element being inserted has key(priority no.) greater than the present elements' keys.Call to insert is insert(start,data,key).

#include<stdio.h>
#include<stdlib.h>

typedef struct node {
    int info;
    int key;
    struct node *next;
}node;

void insfirst(node *ptr,int data,int key)
{
    while(ptr->next!=NULL)
    ptr=ptr->next;
    ptr->next=(node *)malloc(sizeof(node));
    ptr=ptr->next;
    ptr->info=data;
    ptr->key=key;
    ptr->next=NULL;
}

void insert(node *ptr,int data,int key)
{
    node *prev;
    ptr=ptr->next;
    while((ptr->key)<key)
    {
        prev=ptr;
        ptr=ptr->next;
    }
    node *nw;
    nw=(node*)malloc(sizeof(node));
    nw->info=data;
    nw->key=key;
    nw->next=ptr;
    prev->next=nw;
}

int delete(node **start,int *key)
{
    node *ptr;
    ptr=*start;
    ptr=ptr->next;
    int data=ptr->info;
    *key=ptr->key;
    start=ptr->next;
    return(data);
}

void display(node *ptr)
{
    ptr=ptr->next;
    while(ptr!=NULL)
    {
        printf("INFO=%d\t\tKEY=%d\n",ptr->info,ptr->key);
        ptr=ptr->next;
    }
}

int main()
{
    node *start;
    start=(node*)malloc(sizeof(node));
    start->next=NULL;
    int data[10]={5,10,15,20,25,30,35,40,45,50};
    int key[10]={12,31,36,41,49,53,62,76,81,99};
    int op=-1,i,item,ke;
    for(i=0;i<10;i++)
    insfirst(start,data[i],key[i]);
    printf("Initial list:\n\n");
    display(start);
    while(op!=4)
    {
        printf("\nVarious operations available are:\n\n1:Insert\n2:Delete\n3:Display\n4:Exit\n");
        scanf("%d",&op);
        if(op==1)
        {
            printf("Enter the element to be inserted and its respective key\n");
            scanf("%d%d",&item,&ke);
            insert(start,item,ke);
        }
        else if(op==2)
        {
            item=delete(&start,&ke);
            printf("DELETED NODE: INFO=%d\tKEY=%d\n",item,ke);
        }
        else if(op==3)
        display(start);
        else if(op==4)
        exit(0);
    }
    getch();
}