if(window.addEventListener){
   window.addEventListener('load',resizeIframe,false);
 }
else { 
if(window.attachEvent){
   window.attachEvent('onload',resizeIframe);
  }
 }

function resizeIframe() {
if(parent.document.getElementById('the_frame')){
   parent.document.getElementById('the_frame').style.height=
   document.getElementById('container').offsetHeight+'px';
  }
 }