multiple forms one page

Hi all, I am a newbie to PHP. I have several php forms which were originally on separate pages now included in the one page. Each form had the following code in it: function mysql_fix_string($string){ if (get_magic_quotes_gpc()) $string = stripslashes($string); return mysql_real_escape_string($string);} function mysql_entities_fix_string($string){ return htmlentities(mysql_fix_string($string));} However I am only able to include it in one of the forms on the new page with multiple scripts due to the fatal error that I can only declare the function once. So for testing I have commented these lines out of the other scripts. I need to know what the security implications of this are? Do the scripts that do not contain these lines run without it or is it included automatically every time the database is accessed regardless of which script is accessing it? If not how do I deal with it? thanks in advanceRosie