The following raiserror works:

RAISERROR ('CustomerId does not exist in Customer table. Error: %o.', 16, 1, @@ERROR)

Now I want to also print the acctual CustomerId which happends to be stored in the variable @CustomerId (type is nvarchar(10)). How can I get the SP to raise an error with the following message (if CustomerId=einar):

CustomerId einar does not exist in Customer table. Error: 0.

Thanks,
Einar