I like this, here are my comments:
I suggest an even-less invasive approach.
Now you can use the header_onload & get_extra_headers callbacks, so you can include whatever you want from wherever you want.
http://www.openacs.org/forums/message-view?message_id=461497
Also, instead of class=header, better to use the actual ids, and just play with them and javascript, here's my approach:
<script type="text/javascript">
if (top.location != location) {
var siteheader=document.getElementById?document.getElementById("site-header"):null;
siteheader.style.display='none';
var contextbar=document.getElementById?document.getElementById("context-bar"):null;
contextbar.style.display='none';
var navbarx=document.getElementById?document.getElementById("navbarx"):null;
navbarx.style.display='none';
}
</script>
Plus you avoid a loop among all the possible divs.
