unless you need to display content from outside of your server you shouldn't need iframes. if that right hand grey box area is where you want to display some content, and you don't want the site to expand (ie: fixed Height) you can just place some css in there, ex:
Code:
/*css goes in seperate style sheet or head*/
.ContentBox {width:400px; height:450px; background-image:url(/img/greybox.jpg); background-repeat:no-repeat; overflow:auto;}
<!-- html -->
<div class="ContentBox">
your scrollable content goes here
</div>
edit the height and width as needed of course.
if you want to use tables you can still put this div in a column over there.
but yea, try to stay away from Iframes if you aren't pulling outside content, extra page weight and horrible for seo and page rank.
_good luck
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