i have a structure
struct node
{
int element;
struct node* next;
};

in one file "tree_stack.c"
i have other file check_stack.c in which stack is implemented.This file contains the structure
struct st
{
struct node* nd;
struct st* nxt;
}

i have to use struct node in this check_stack.c file.So i have included this file in "tree_stack.c".
i have used it as extern struct node *nd.
but when i try to access a data
like
curr->nd->element // produces error
where curr is
struct st* curr;

i am getting error of smth like "accessing incomplete data ".
anyone got clue??
guide me where i am wrong and how to correct it.
thanks