Spell Problem : JASS help?

I have a problem, I want to create a spell that simply replaces one unit with another. Unfortunately bearform does not like to work with out being upgraded. I then tryed to trigger it, but discovered there was no event that is like "Unit of type casts a spell"

If anyone could help me a ton, all I would need is a spell that simply turns a unit into another. Just use placeholders for the units in the meantime.

If anyone could do that, it would be a great help, since I have been stuck on this for a month now.

Thanks,
Fiery_Maelstrom

Events
-A unit owned by player 1 (red) is issued an order with no target
Conditions
-(issued order) equal to (whatever)
Actions
-Replace (ordered unit) with a (whatever), using the old unit's relative life and mana

That should be it! :D

I know about that way, but I am wondering if there is a quicker way, since I do not want to have to make 8 triggers like this for every player (could be up to 12). 12*8 does not sound fun.

If there is a more broad way, ie: Current player or any player instead of refering to each player directly, that would be helpful to know about, thanks!

-Fiery_Maelstrom

Hmm... maybe this will work?

Events
-A unit owned by player 1 (red) is issued an order with no target
-A unit owned by player 2 (blue) is issued an order with no target
-A unit owned by player 3 (teal) is issued an order with no target
-A unit owned by player 4 (purple) is issued an order with no target
-A unit owned by player 5 (yellow) is issued an order with no target
-A unit owned by player 6 (orange) is issued an order with no target
Conditions
-(issued order) equal to (whatever)
Actions
-Replace (ordered unit) with a (whatever), using the old unit's relative life and mana

I will try that, thanks!

-Fiery_Maelstrom