function popUp(URL,popW,popH) {

var w = 500, h = 500;

if (document.all || document.layers) {
   w = screen.availWidth;
   h = screen.availHeight;
}

var topPos = 0, leftPos = (w-popW-20);


   window.open(URL,'popup','resizable, toolbar=no, location=no, status=no, scrollbars=no, menubar=no, titlebar=no, width=' + popW + ',height=' + popH + ',left=' + leftPos + ',top=' + topPos + ',screenX=' + leftPos + ',screenY=' + topPos);
}