edmx and get the values from the entities?

Hi friends,

i have an edmx file called Customers.edmx which has an entity (Sql Serv view) CustomeDetails with the following fields in it :
Customerid, CustomerName,Userid.
In the Customerpage.aspx when the customer comes to this page i want to retrieve the customer ID from the CustomerDetails entity  based on the
userid (user.identity.Name.ToString).  What is the best possible way of doing this in the code behind of the CustomerPage.aspx.

Thank You