function openWindow(url, w, h, windowname) {
	var oxW=0;
	var oyH=0;
	if (window.innerHeight) {
		// Firefox
		oxW = window.innerWidth; oyH = window.innerHeight;
	} else if (document.documentElement.clientHeight > 0) {
		// IE
		oxW = document.documentElement.clientWidth; oyH = document.documentElement.clientHeight;
	} else {
		// Other
		oxW = document.body.clientWidth; oyH = document.body.clientHeight;
	}
	var options = "";
	options += "resizable=yes,scrollbars=yes,status=yes,";
	options += "menubar=no,toolbar=no,location=no,directories=no";
	options += ",width=" + w;
	options += ",height=" + h;
	options += ",top=" + (window.screenY + (oyH/2) - (h/2));
	options += ",left=" + (window.screenX + (oxW/2) - (w/2));
	var newWin = window.open(url, windowname, options);
	newWin.focus();
}