function OpenPopUp(url, width, height) {
	OpenPopUpExtended(url, width, height, 'taz_popup');
}
// opens a pop up
function OpenPopUpExtended(url, width, height, win_name) {
	if (isNaN(width) || (width==0)) {
		width = 620;
	}
	if (isNaN(height) || (height==0)) {
		height = 400;
	}

	var win_name = String(win_name);
	if (win_name.length == 0) {
		win_name = 'popup';
	}

	x = (screen.width - width) / 2;
	y = (screen.height - height) / 2;

	var str_url = String(url);
	if (str_url.length > 0) {
		var style = "toolbar=no,location=no,directories=no,menubar=no,scrollbars=yes,resizable=yes,status=no,width=" +
								width + ",height=" + height + ",left=" + x + ",top=" + y;
		var popup = window.open (str_url, win_name, style);
		popup.focus();
	}
}