function popup(url,winName,W,H,X,Y) {
	X = screen.width/2-W/2;
	Y = screen.height/2-H/2;
	winprops = 'height='+H+',width='+W+',top='+X+',left='+Y+',scrollbars=no';
	win = window.open(url, winName, winprops);
	if (parseInt(navigator.appVersion) >= 4) {
		win.window.focus();
	}
}