I'm working on a complex rule for a mail merge field ...

If mail merge field 'r1_relchg' is blank (="") then display "", otherwise display 'r1_sru' (h:mmA/P) - 'r1_srl' (h:mmA/P)

An example of the presentation if r1_relchg <> "" might be:

9:00A-9:30P

I am not certain how, if its possible, to concatenate the 'r1_sru', '-'. and 'r1_srl'