function doIframe(){
   o = document.getElementsByTagName('iframe');
   for(i=0;i<o.length;i++){
      if (/\bautoHeight\b/.test(o[i].className)){
         setHeight(o[i]);
         addEvent(o[i],'load', doIframe);
      }
   }
}

function setHeight(e){
   if(e.contentDocument){
      e.height = e.contentDocument.body.offsetHeight + 35;
   } else {
      e.height = e.contentWindow.document.body.scrollHeight;
   }
}

function addEvent(obj, evType, fn){
   if(obj.addEventListener)
   {
   obj.addEventListener(evType, fn,false);
   return true;
   } else if (obj.attachEvent){
   var r = obj.attachEvent("on"+evType, fn);
   return r;
   } else {
   return false;
   }
}

if (document.getElementById && document.createTextNode){
 addEvent(window,'load', doIframe);
}