Cost Center Check In Service Entry

Hello,

( a) I want to do a cost center check in SES without affecting release strategy. Which exit to use ?

(b) With the exit SRVREL, I'm able to do the check, but it deactivates the release strategy. Is there anyway to have activate release strategy when SRVREL is used for cost center check ?

(c) I have also used the exit SRVESKN, but it gets triggered before the screen entry of the cost center. How can I make it trigger after screen entry of the cost center ?

Thanks & regards,

Sheeja.