Replacing ImageMap hangs IE6 - weird problem

Hi,

I'm wondering how can I realise such scenario:
there is an image with a image map. I click on area and now current map is
switched with another image map where that clicked area isn't active now.
Right now I'm doing something like this (using DOM):

<script type="text/javascript">
function setSrc(name) {
var x=document.images
x[0].useMap="#" + name;
}
</script>

But that code simply hangs IE6 (but not Mozilla and Opera). So, how can I
replace this code to something more compatible with all browsers. You can
test this behavior here http://krzyki.eu.org/test/test.html (click on Mapa 2
area).

I was trying to use <div id="..."> and replacing .innerHTML with map
definition, but the result is the same.

Any ideas?

Greetigns
Radek Michalski