Modules pages

function modules(){ if(isset($_GET)){ $op = $_GET; $g = chr(92); $op = str_replace($g , "", $_GET); $op = str_replace("/" , "", $op); $op = str_replace("-" , "", $op); $op = str_replace(";" , "", $op); $op = str_replace("'" , "", $op); $op = str_replace("%00" , "", $op); $op = str_replace("?" , "", $op); $op = str_replace("$" , "", $op); $op = htmlspecialchars($op); if (is_file("modules/".$op.".php")) { include("modules/".$op.".php"); } else { require("config.php"); Echo (" Module $op not found. "); } } }