For years Joomla has had a small script used to adjust the hight of a frame: function iFrameHeight() { var h = 0; if ( !document.all ) { h = document.getElementById('blockrandom').contentDocument.height; document.getElementById('blockrandom').style.height = h + 60 + 'px'; } else if( document.all ) { h = document.frames('blockrandom').document.body.scrollHeight; document.all.blockrandom.style.height = h + 20 + 'px'; } } Just recently it has stopped working in FF & Chrome. I have altered it to use .contentDocument.body.scrollHeight But when did contentDocument.height disappear?