real = false;
function PopUpWindow(urlString, name, w, h) {
	var winX = 0;
	var winY = 0;
	if (parseInt(navigator.appVersion) >= 4) {
		winX = (screen.availWidth - w)*10*.01;
		winY = (screen.availHeight - h)*10*.01;
	}
	if (real) {
	    popupWin.close();
	}
	popupWin = window.open(urlString, name, 'width=' + w + ',height=' + h + ',left=' + winX + ',top=' + winY +', toolbar=no,location=no,status=no,menubar=no,scrollbars=yes,resizable=no');
    real = true;
}