You may have to set the height and width of the div so that they are the same size as the images. then add borders.heres an example.
<html><head><style type="text/css">#imageborederdiv{width: /*make this value the same as the image*/height: /*once again set to sam e as div*/border-color:/*choose a colour*/border-style-type:/*pick one I use solid*/border-width: /*A tiny border is 1-2px a noticapble one is 4-7px an off the scale on is anything highers*/}</style><body><div id="imageborderdiv"><img src="<!--where you put the image-->" /></div></body></html>
There are things that can be added to this for a better look and feel but this will probably cut it. If you ever need any help I like being PMed