// 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;
  if (!url) return true;
  w = (w) ? w += 20 : 150;  // 150px*150px is the default size
  h = (h) ? h += 25 : 150;
  var args = 'width='+w+',height='+h+',scrollbars=no, toolbar=no,status=no,resizable=yes,menubar=no,location=no,directories=no';
  popdown();
  pop = window.open(url,'',args);
  return (pop) ? false : true;
}

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

<!--
function findObj(n, d) { //v4.01
 var p,i,x; if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
 d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
 if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
 for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=findObj(n,d.layers[i].document);
 if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function showHideLayers() { //v6.0
 var i,p,v,obj,args=showHideLayers.arguments;
 for (i=0; i<(args.length-2); i+=3) if ((obj=findObj(args[i]))!=null) { v=args[i+2];
 if (obj.style) { obj=obj.style; v=(v=='show')?'visible':(v=='hide')?'hidden':v; }
 obj.visibility=v; }
}
//-->