THe best place to find them is by searching this forum, there are a couple of good examples in here, as well as on the PHP.net pages. Have a look as well on the PHPBuilder.com tutorials page - I am sure I have seen one there in the past.
Failing that - the best course of action is to try, try and try again - if you are having problems with the script, post it in here and we'll be able to help you with it. Most aspects of it are relatively easy once you have seen a couple of examples.
