Verify email address by sending activation code in ASP.Net

Hi,   I have to validate the email addresses. For that an email containing verification link is sent to the candidates while registering. By clicking the link the database will be updated with the status of email id as verified. How can I pass the username or other details of the candidates through the verification link?   I am using asp.net with c# coding.   Have any other good methods to implement email verification? Kindly help me....   Thank you.....