<style>
IMG {}
.thumb {}
.fullsize {}
</style>
<Style>
IMG {put common attributes in here,
such as if they both won't have a border}
.thumb {put style attributes in here that are only
associated to the thumbnail pic, which will
more than likely be width and height}
.fullsize {put style attributes in here that are only
associated with the full pic - I think if you
eliminate the width and height attributes from
the IMG, you will get the default size which
should be the largest}
</Style>