sql server - an expression of non-boolean type specified in a context sql -

I can not get it to work Arrival! I'm trying to add additional and if @ DisiscountName is a fixed value too much I am trying to add additional and statement if the incoming parameter @ disconnectname = "mylue"

  optional process [ Dbo]. [Usp_Discount_InsertDiscountBatch] @CustomerNumber Int, @DiscountName Varchar (50) [Transaction Activity]. [Transaction activity] where [dba] [Transaction activity]. Customer number = @ Customer number and case when @discetmail = 'Member' then [DBO]. [Transaction Activity]. ISMMBS Else 'End End'  

This is for MS SQL Server.

It is not clear what you want probably something like this:

 < Code> where [dbo] [Transaction Activity]. Customer number = @ Customer number and (Discount name