Random #'s with a twist

I’m venturing away from my ASP comfort zone to write what, on the surface, seems like a fairly simple script in PHP.

I have a small table that is a single row of 5 thumbnail images showing featured products. I want to select these five items at random from a specified list of items. Sounds easy enough, just generate five random numbers. BUT, how do I go about making sure that I have no duplicates?

Perplexed in Texas :puzzle: