C program to implement linked list

#include<stdio.h>
#include<conio.h>
#include<alloc.h>
struct list
{
int data;
struct list *next,*prev;
}*head=NULL;
void main()
{
void insert();
void del();
int c;
clrscr();
 
/****************************************************************/
 
printf("\n\tOUTPUT::\n");
printf("\n\t1:insert \t\t2:delete\n\t3:exit");
while(1)
{
printf("\n\tENTER CHOICE: ");
scanf("%d",&c);
switch(c)
{
case 1: insert();  break;
case 2: del();  break;
case 3: exit(1);
}
}
}
/*************************************************************/
void insert()
{
struct list *temp,*new1,*pr;
int pos,i=1;
char ch;
temp=head;
printf("\tENTER POSITION TO BE INSERTED: ");
scanf("%d",&pos);
new1=(struct list*)malloc(sizeof(struct list));
printf("\tENTER DATA: ");
scanf("%d",&new1->data);
if(pos==1)
{
new1->next=temp;
head=new1;
}
else
{
while(i
<pos)
{
pr=temp;
temp=temp->next;
i++;
}
temp->prev=new1;
new1->next=temp;
new1->prev=pr;
pr->next=new1;
}
}
/****************************************************************/
void del()
{
struct list *temp,*pr,*t;
int pos,i=1;
temp=pr=head;
printf("\tENTER POSITION TO BE DELETED: ");
scanf("%d",&pos);
temp=head;
while(i
<pos)
{
pr=temp;
temp=temp->next;
i++;
}
t=temp;
temp=temp->next;
pr->next=temp;
temp->prev=pr;
free(t);
}