i can stand up and fire so what can i use to stop that from happening
Do you want him to not stand, not fire or both not stand and not fire?
If you do not want him to fire, remove his ammo and replace it later when/where it is needed.
As for the not standing, shoot his kneecaps! ;D
But seriously, that is the only thing that I can think of. Just set his damage to a point where he cannot stand, and revert it back when you give him his ammo back.
Of course, this would work but I am not sure of the damage level needed so it may make the unit all bloody.
This may not be the best of solutions, but it is the only one posted so far (I hate to see questions go unanswered as it is so un-OFPEC like!).
Wadmann