> How can I ensure that a file with the extension .jpg or .gif 
> really IS a 
> picture, and not just a random file that has been renamed?

goto http://abstractvb.com/code.asp?CID=30
you'll find the code to extract the header info from a jpeg, you should be
able to use this to verify that it has at least a valid header and so can be
displayed...and for gifs try http://abstractvb.com/code.asp?CID=29

k