Paladin Crusader/Mount macro?

[TooNasty]

Ive been trying to macro but just can't seem to get it right so Im looking for some help.
I want a macro for my paladin that does a few things:

If I can fly, summon my flying mount.
If I can't fly, summon my charger.
When I mount cast Crusader aura.
When I dismount go back to Ret aura.

Is this possible?

[Deleted]

#showtooltip
/cast [mounted]Retribution Aura; Crusader Aura
/cast [nomounted, flyable]Flying Mount; [nomounted]Summon Charger
/dismount [mounted]