In my opinion the after statement is just for simulation purposes. So everything you put into your vhdl-code in this example will take place simultanious.
Try a different way to delay your code like usleep or built some kind of counter into the code, but this won't work like you try it right now. But sorry I haven't got a solution right away. Here is a link to an example, where I showed how to delay an led with a modulo-counter, but it is a block design just look into the attachment.
http://www.alteraforum.com/forum/showpost.php?p=85568&postcount=6 Good luck!