Something

<?php

function ondelete(){
	$dialog = new GtkMessageDialog(null,
	0,
	Gtk::MESSAGE_QUESTION,
	Gtk::BUTTONS_YES_NO,

	'Ben je zeker dat je de Site Tracker wilt afsluiten?');
	//$dialog->set_icon_from_file(LD . DS . 'img' . DS . 'tracker_16.png');
	$dialog->set_title('Afsluiten?');
	
	
	if($dialog->run() == Gtk::RESPONSE_YES) {
	$dialog->destroy();
		return flase;
	}else{
		$dialog->destroy();
	return true;
	}
}

$wnd = new GtkWindow();
$wnd->connect_simple('destroy',array('gtk','main_quit'));
$wnd->connect_simple('delete-event','ondelete');
$wnd->show_all();

Gtk::main();