note 95494 added to function.isset

I would like to ask: If I want to display the whole page of "abc.php" in "index.php?action=abc", Can I use this script? <?php if(isset($_GET['action=abc'])) { include_once('abc.php'); } ?> How can I display this page correctly? ---- Server IP: 69.147.83.197 Probable Submitter: 119.236.59.147 ---- Manual Page -- http://www.php.net/manual/en/function.isset.php Edit -- https://master.php.net/note/edit/95494 Del: integrated -- https://master.php.net/note/delete/95494/integrated Del: useless -- https://master.php.net/note/delete/95494/useless Del: bad code -- https://master.php.net/note/delete/95494/bad+code Del: spam -- https://master.php.net/note/delete/95494/spam Del: non-english -- https://master.php.net/note/delete/95494/non-english Del: in docs -- https://master.php.net/note/delete/95494/in+docs Del: other reasons-- https://master.php.net/note/delete/95494 Reject -- https://master.php.net/note/reject/95494 Search -- https://master.php.net/manage/user-notes.php