Return Nth the node from the end of the linked list

#include<stdio.h>
#define null 0
typedef struct list
{
int n;
struct list *next;
}node;

node *findmthnode(node *s,int m)
{
int i;
node *h1=s,*h2=s;
for(i=1;i<=m;i++)
{
   if(h1==null)
     return null;
   h1=h1->next;
}
while(h1)
{
   h1=h1->next;
   h2=h2->next;
}
return h2;
}

main()
{
node *h=null,*new1=null,*prev,*t;
char ch;
int k,m;
do
{
   printf("\n Enter the number to inseret into list ");
   scanf("%d",&k);
   new1=(node *)malloc(sizeof(node));
   new1->n=k;
   new1->next=null;
   if(h==null)
   {
	h=new1;
	prev=new1;
   }
   else
   {
	prev->next=new1;
	prev=new1;
   }
   getchar();
   printf("\n Press Y or y if U Want to continue enter the no's ");
   scanf("%c",&ch);
}while(ch=='y' || ch=='Y');
printf("\n List Is ");
t=h;
while(t!=null)
{
   printf(" %d",t->n);
   t=t->next;
}
do
{
   printf("\n Enter value of m (not 0) to find the mth node from end of the list");
   scanf("%d",&m);
   if(m!=0)
   {
	t=findmthnode(h,m);
	if(t==null)
	{
	   printf("\n m is greater than the total no of nodes");
	}
  	else
	{
	   printf("Value Of Node %d from the end of list is %d",m,t->n);
	}
   }
}while(m!=0);
}