// Script by Thomas Stich
// http://www.stichpunkt.de/beitrag/popup.html
// use it if you like it
//
// <a href="html-or.jpg" onclick="return popup(this,123,456)" title="..."
// or
// <a href="html-or.jpg" onclick="return popup(this)" title="..."


var pop = null;

function popdown() {
  if (pop && !pop.closed) pop.close();
}

function popup(obj,w,h) {
  var url = (obj.getAttribute) ? obj.getAttribute('href') : obj.href;
  isInternetExplorer = navigator.appName == 'Microsoft Internet Explorer' && document.documentElement && navigator.userAgent.indexOf ('Opera') == -1

  if (isInternetExplorer) {
    var addheight = 25;
    var addwidth = 20;
  } else {
    var addheight = 0;
    var addwidth = 0;
  }

  if (!url) return true;
  w = (w) ? w += addwidth : 150;  // 150px*150px is the default size
  h = (h) ? h += addheight : 150;
  var args = 'width='+w+',height='+h+',resizable';
  popdown();
  pop = window.open(url,'',args);
  return (pop) ? false : true;
}

window.onunload = popdown;
window.onfocus = popdown;