Function Not define

[Anon]

I have an include file it it include a t the top of my page

include('user_chk.php');

Then the function on submit
if ($submit) {
user_login($user_name,$password);
}

well there is no error that the user_chk is not include but when I hit submit I get

Fatal error: Call to undefined function: user_login()

code can be provide if needed but straight forward function cant see why it not working