Creating a dynamic website header.

I don't even know where to start with this one, let me try explain this: I am looking for ideas on how to create some sort of dynamic header for an affiliate website, we have launched a new affiliate program for <[login to view URL]> the affiliate program is done through [login to view URL] and each affiliate is given an ID like: <[login to view URL]> Once the affiliate signs up they choose their own website URL like: [login to view URL], then we point the affiliate URL [login to view URL] to <[login to view URL]> which in turn comes to our main website: <[login to view URL]> now here is where the problem comes in, how do I make the website display Mikes Health instead of African Cures . * * *I think it is even easier than what? we think, I would need to have a list stored with all the affiliate IDs and then their related 'Web Names' eg: aff ID#812264 = 'Mikes Health Store'. Then when the person types in [login to view URL] the url redirects using <[login to view URL]>, somehow the site [login to view URL] pulls out the 812264 and then displays 'Mikes Health Store' in place of 'African Cures', and updates the title: <title>African Cures | Prosit </title> to <title>Mikes Health Store | African Cures </title> The other issue that I see is that when they go off the site for a while to purchase the product and they come back from the shopping cart, how will the site know it is them returning and then display 'Mike Health Store' again? * * *