ASP.net MVC2

Question

Hi Experts

In my application i am passing a customised link in the email to customers .
the sample link will be something like this http://home.vasudevula/?cid=5a2d

I want to capture the cid from the query string when the user hits the link and update the database with a flag like this email is active.I have written a webmethod to update the databse but i want to know how to capture the cid on the fly and display a page saying congartulations you have registered if i find a match for a cutomer having the same cid in the databse.If  i am unable to verify the cid i will show a blank page or an error page.


I am new to this mvc stuff.Please help.