var winPopup = null;

function openWindow(url, name, width, height, scrollbars, resizable){
	if(winPopup != null && !winPopup.closed)
		winPopup.close();
	var left = Math.round(screen.width / 2) - Math.round(width / 2);
	var top = Math.round(screen.height / 2) - Math.round(height / 2);
	winPopup = window.open(url, name, "width = " + width + ", height =  " + height + ", top = " + top + ", left = " + left + ", scrollbars = " + scrollbars + ", resizable = " + resizable);
	winPopup.focus();
}