there is two way you can do this (there is more). using the function include() to include files based on query string or using call_user_func()
you can keep all the files/modules in one folder. pass the module reference using GET. from the GET we can determine which function we want to call using include() or call_user_func() be careful, do not pass the filename for the include because it used to be some security problem. you can do an array instead $modules['gallery'] = 'gallery.php'; //gallery.php is filename so we can pass the modules to the program as eg: www.domain.com/?mod=gallery then do include($module[$_GET['mod']]); you can use file_exists() function to determine the file actually exist prior to the include().. good luck..
