function openPopup (name, reqWidth, reqHeight, event)
{
	var winWidth, winHeight;

	if ((winWidth = reqWidth + 20) > screen.availWidth) {
		winWidth = screen.availWidth;
	}
	if ((winHeight = reqHeight + 20) > screen.availHeight) {
		winHeight = screen.availHeight;
	}
	window.open (
		name,
		'Image',
		'width=' + winWidth + ',' +
		'height=' + winHeight + ',' +
		'channelmode=no,' +
		'directories=yes,' +
		'fullscreen=no,' +
		'location=no,' +
		'menubar=no,' +
		'resizable=yes,' +
		'scrollbars=yes,' +
		'status=yes,' +
		'titlebar=yes,' +
		'toolbar=no',
		false
	);
	if ('preventDefault' in event) {
		event.preventDefault ();
	} else if ('returnValue' in event) {
		event.returnValue = false;
	}
}