function openPopup(url, name, w, h) {
               if (document.all) {
                  var winX = (screen.availWidth - w)*.5;
                  var winY = (screen.availHeight - h)*.5;
                  popupWin = window.open(url, name, "status=no,scrollbars=yes,menubar=no,toolbar=no,width=" + w + ",height=" + h + ",left=" + winX + ",top=" + winY);
               } else {
                  var winX = window.screenX + ((window.outerWidth - w) / 2);
                  var winY = window.screenY + ((window.outerHeight - h) / 2);
                  popupWin = window.open(url, name, "status=0,scrollbars=1,menubar=0,toolbar=0,width=" + w + ",height=" + h + ",screenX=" + winX + ",screenY=" + winY);
               }
            }