CSS - Strecthing

Hi all,

I was wondering if there was a way to stop an image stretching in all browsers.

I'm creating a gallery for my web page. I've got a load of thumbnails that when you click on one it will display the picture lower down on the page. This image is in a DIV with a set width.

The trouble is that some images could be small, some could be large.

Using CSS I've tried setting the width to something like the size of the containing DIV. This works great for large pics but stretches the smaller pics (obviously it would as I was specifing a width). I then tried max-width. Hurrah, in Firefox this works great. Of course, Internet Explorer being the pile of poop that it is, my images come out huge and throw off the layout.

is there an easy way to ensure that my small images stay small but my large images don't grow too large for both IE & Firefox using CSS?

If not I guess I'll use PHP to determine the image size and go from there.