well no, if you think about it, the JS is only active one the page loads (or your HTTP state is 4)
so actually the Jscript is seiving through your full code and since the browserss renders your <img src="img1.jpg" /> to <img src="http://www.mysite.com/images/img1.jpg" /> then the Jscript sees "src='http://www.mysite.com/images/img1.jpg'" and not "src=img1.jpg" />
Make any sense?
Boog's