When I switch this:
<div class="zoom">
<a href="javascript:zoomImage();" class="btn-zoom">view larger image</a>
</div>
to this:
<div class="zoom">
<a href="/zoomimg.jpg" onclick="zoomImage()" class="btn-zoom">view larger image</a>
</div>
I get an error that the zoomImage() function couldn't be found.
Here's an example page: http://www.avaline.com/102
The function is defined near the end of the page, but I didn't click on the link until after the page loaded.