function openPrecise(url, name, w, h) {
		// initialize winX and winY to default values
		// for cases where Screen object isn't supported
		var winX = 0;
		var winY = 0;

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

		popupWin = window.open(url, name, 'width=' + w + ',height=' + h + ',left=' + winX + ',top=' + winY + 'scrollbars = no');
	  	}