Requested WoW macro

If possible I would like the macro to cast avenging wrath (on cd) or Execution sentence (on cd) when crusader strike is used. I have been experimenting but can only get partial functionality eg: the macro works when execution sentence is off cooldown but does not allow crusader strike to be cast otherwise.

essentially:

If Avenging wrath is off cooldown
Cast Avenging wrath
OR
IF Execution Sentence is off cooldown
Cast Execution sentence
THEN
Cast crusader strike

Thanks.