function PopWin(url,w,h) {
wx=w;
wy=h;

xww=(screen.width -wx)/2;
yww=(screen.height -wy)/2;

var param ='left='+xww+',top='+yww+',width='+w+',height='+h+',scrollbars=yes,resizable=yes,menubar=yes';
var win;
win=window.open(url,"pop", param);
win.focus();
}