How do i write code to handle exceptions in the DAL if i use the designer to create DAL?

Question

hi,
It seems like i have to use the Designer to create DAL with Optimistic concurrency. Typically when i write DAL without Optimistic concurrecy i got the previledge to write code to handle exception such as errors in connecting to DB ..etc within the DAL. but now use of the designer to create DAL i dont get the chace to write code to handle exceptions. how do i implement exception handling in the DAL if i use the designer?
TY