It just occurred to me that an iframe is an inline element, so you don't need to do anything special. Just put the iframe in the crawler. The script should do the rest:
And you don't want it to have scrollbars, so that part is fine. Just follow the above with your chosen init, something like:
<div id="mycrawler" class="marquee">
<iframe NAME="Alert1" width="958" height="20" scrolling="no"
Best place for that is right before the closing </body> tag of the page.
'border': '1px solid #CC3300'
inc: 5, //speed - pixel increment for each iteration of this marquee's movement
mouse: 'cursor driven', //mouseover behavior ('pause' 'cursor driven' or false)
Even with this method, make sure you have the right to display that other site's content before proceeding.