function openWindow(url,pheight,pwidth) {
	// initialize winX and winY to default values for cases where Screen object isn't supported
	var winX = 0;
	var winY = 0;

	var w = 0;
	var h = 0;
	
	w = pwidth;
	h = pheight;
	
	// only set new values if 4.0 browser
	if (parseInt(navigator.appVersion) >= 4) {
		winX = (screen.availWidth - w)*.5;
		winY = (screen.availHeight - h)*.5;
	}

	winOpts = "toolbar=no,location=0,directories=no,status=no,menubar=0,scrollbars=0,resizable=0," + "width=" + w + ",height=" + h + ",left=" + winX + ",top=" + winY
	popupWin = window.open(url, "popupName", winOpts);
}