Call: 
if (search(ptr,key))
     printf("The key is in the list\n");
else
	printf("The key is not in the list\n");

list_pointer search(list_pointer ptr, int key)
{/* determine if key is in the list */
  list_pointer temp;
  for (temp = ptr; temp; temp = temp->link) 
        if (temp->item.key == key) return temp;
  return NULL;
}