no,it should be.
if IsButtonBeingPressed(7,0) and IsButtonBeingPressed(0,0) then
repeat
PedLockTarget(gplayer,-1)
PedSetAITree(gPlayer, "/Global/DarbyAI", "Act/AI_DARBY_2_B.act")
PedSetActionNode(gPlayer, "/Global/Nemesis/Offense/Short/Strikes/LightAttacks/JAB/HeavyAttacks/SuperUppercut/Knee", "Act/Anim/Nemesis.act")
PedSetAITree(gPlayer, "/Global/PlayerAI", "Act/PlayerAI.act")
Wait(0)
until PedIsPlaying(gPlayer, "/Global/Nemesis/Offense/Short/Strikes/LightAttacks/JAB/HeavyAttacks/SuperUppercut/Knee", "Act/Anim/Nemesis.act")
end