function openWindow(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);
}