Why T_error?

I, once I found out that register_globals isn't always one, have always done HTTP variables as like $_SESSION for session and $_POST for form vars through post. Why, if you have register_globals off does it return T_error? Should I jsut replace my old ways with $HTTP_SESSION_VARS for sessions and $HTTP_POST_VARS for posted form vars from now on or what? Thanks, Stephen Craton http://www.melchior.us "What's the point in appearance if your true love, doesn't care about it?" -- http://www.melchior.us