Dynamic Picture Gallery : How To

I have developed an asp dynamic picture gallery, which reads the contents of the folder on the server & if they are pictures, display their thumbnails in the html table, on clicking any thumnail, you 'll get the big picture.

I didn't use any database in it, while I did it with File System Object of ASP, is it a right approach to develope. Because we are showing the contents of our web directory of server to the end user. or some server can create trouble for us while reading content from server hard disc...