code improvement before i go further!!

Hi everybody,

i was performing some linked list operations,
the code below adds node to the end of the list by using function
add_node().

first i created a node in main() and then the program asks the user
if he needs any more. now i am going to add other link list operations like delete etc.

Kindly guide if lacking any good programming style or the code below can hav improvements.

Thanks

Code:

#include<stdio.h>
#include<conio.h>
struct node{
               int key;
               struct node* next;
           };
           
void add_node(struct node* start) { 
   struct node* temp;
   char ch;
   temp=start;
  
   while(temp->next!=NULL)
      temp=temp->next;
  
  struct node* nd;
  nd=(struct node*)malloc(sizeof(struct node));
  printf("Enter node value\n");
  scanf("%d",&nd->key);
  
  temp->next=nd;
  nd->next=NULL;
  
  printf("Do you want to add another node(y/n)\n");
  ch=getch();
  if(ch=='y')
     add_node(start);
  else
     return; 
    
}

int main()  
         
{ 
  struct node* start,*p,*q;
  
  start=(struct node*)malloc(sizeof(struct node));
  printf("Enter first node value\n");
  scanf("%d",&start->key);
  start->next=NULL;
  
  add_node(start);
  
  for(p=start;p!=NULL;p=p->next)
  printf("%d\n",p->key);
  
  for(p=start;p!=NULL;p=q) {
      q=p->next;
      free(p);
    }  
  
  getch();
  return 0;
}

Why, are you going to pay attention this time?
urgent regarding malloc()

hey salem,

friend i am ready put in the effort as required because i want to improve each day.
Thats all i can say. now its upto u if u can help me.

Thanks