I developed a members registration system for my game site which gives the members special privileges. Please check and give me some feedback about it The link: http://www.gamestoenjoy.com/site/index.php?option=com_content&view=article&id=1257
In terms of UX it's failing pretty bad. JavaScript should be used for error handling and have a fall back written in PHP for those strange users who disable it. Have a look at this: http://malsup.com/jquery/form/ Should save you a lot of time rather than having to learn how to code JS overnight.
A registration system usually includes a settings page where I can edit information you have and change my email and/or password. I couldn't find that. Are you storing the passwords as plain text or are you hashing them?