Update Existing System -- 2

I need upgrade my system to add in one small module, to record down security check time for a visitor. When a visitor visit a site, they will need to register in guard house and for first time visitor need to perform a security check. After done, guard will need to key in the data in the new module. The data key in just like visitor id and name, creation date and time, security check date and time, and expirt date (preset 1 year after check date). And in the Vesiter registration page(existing module), need add a checking for the expiry date, if expire, then need to perform one more time security check and key in system. Please put a reminder on the expiry date (preset 90days before expire, but allow to change the days), when user register, pop up a reminder if expiry soon. And on the new module, add in a list to show those expire soon visitor. The system currently in MS Visual Studio 2012 Vb.net. And database is MS SQL Server 2008 R2