/**
  * @throws SystemMessageIDMissingException
  */
 public static function delete()
 {
     if ($_GET['id']) {
         $system_message = new SystemMessage($_GET['id']);
         if ($_GET['sure'] != "true") {
             $template = new HTMLTemplate("base/admin/system_message/delete.html");
             $paramquery = $_GET;
             $paramquery['sure'] = "true";
             $params = http_build_query($paramquery);
             $template->set_var("yes_params", $params);
             $paramquery = $_GET;
             unset($paramquery['sure']);
             unset($paramquery['action']);
             unset($paramquery['id']);
             $params = http_build_query($paramquery, '', '&');
             $template->set_var("no_params", $params);
             $template->output();
         } else {
             $paramquery = $_GET;
             unset($paramquery['sure']);
             unset($paramquery['action']);
             unset($paramquery['id']);
             $params = http_build_query($paramquery, '', '&');
             if ($system_message->delete()) {
                 Common_IO::step_proceed($params, "Delete System Message", "Operation Successful", null);
             } else {
                 Common_IO::step_proceed($params, "Delete System Message", "Operation Failed", null);
             }
         }
     } else {
         throw new SystemMessageIDMissingException();
     }
 }