Getting MAC address through a Web Page

Hello, I have an Auction Platform website, I badly need to stop some users to figure out chill bidding on my site, through knowing a the MAC address of the user.. I know this is a bit tough job because most of the users are behind LAN so server side code will not work, People told me that it can be done through Flash object and Flex code, I'm not that experienced with these tools... Anybody has any idea how to get this done, All what I need is to get a page where I as a user click on button or something, then the next page I can see my MAC address... If you can deliver this, no art work is needed, I will choose immediately Thanks, Aboud