Global Change to Add the WBS name with the activity name

Dear All

i tried to add the WBS name  starting of each  activity which falls in that WBS.

i used the global change

where

blank....

then

activty name  =  activty name  & wbs name

by this i got the result such as

earlier- issue permit

after global change-UNIT21issue permit

now my problem is i want to have - or space between theese two like UNIT21- issue permit or UNIT21  issue permit

Please guide me

thanks in advance