doubly linked list c

/* Node of a doubly linked list */
struct Node { 
    int data; 
    struct Node* next; // Pointer to next node in DLL 
    struct Node* prev; // Pointer to previous node in DLL 
};

//delete first item
struct node* deleteFirst() {

   //save reference to first link
   struct node *tempLink = head;
	
   //if only one link
   if(head->next == NULL) {
      last = NULL;
   } else {
      head->next->prev = NULL;
   }
	
   head = head->next;
	
   //return the deleted link
   return tempLink;
}

//insert link at the first location
void insertFirst(int key, int data) {

   //create a link
   struct node *link = (struct node*) malloc(sizeof(struct node));
   link->key = key;
   link->data = data;
	
   if(isEmpty()) {
      //make it the last link
      last = link;
   } else {
      //update first prev link
      head->prev = link;
   }

   //point it to old first link
   link->next = head;
	
   //point first to new first link
   head = link;
}