I was able to load internal pages with full width successfully using this
<script type="text/javascript">
function calcHeight()
{
//find the height of the internal page
var the_height=
document.getElementById('the_iframe').contentWindow.
document.body.scrollHeight;
//change the height of the iframe
document.getElementById('the_iframe').height=
the_height;
}
</script>
<iframe width="100%" src="/mypage.php"
scrolling="no" id="the_iframe" onLoad="calcHeight();" height="1px" frameborder="0" ></iframe>
This is working great for any INTERNAL pages (page from same domain). I am struggling to get it work with external pages (cross-domain) but didnt find any solution.
IT SEEMS IT IS IMPOSSIBLE TO DO CROSS DOMAIN COMMUNICATION WHICH I REALLY DIDN'T EXPECT. WHATEVER, THANK YOU ALL.