How to set iframe size dynamically

If you use jquery, it can be done by using $(window).height();

<iframe src="html_intro.asp" width="100%" class="myIframe">
<p>Hi SOF</p>
</iframe>

<script type="text/javascript" language="javascript"> 
$('.myIframe').css('height', $(window).height()+'px');
</script>

Not quite sure what the 300 is supposed to mean? Miss typo? However for iframes it would be best to use CSS :) - Ive found befor when importing youtube videos that it ignores inline things.

<style>
    #myFrame { width:100%; height:100%; }
</style>

<iframe src="html_intro.asp" id="myFrame">
<p>Hi SOF</p>
</iframe>