Trouble Animating an NPC rig that contains a humanoid?

local animation = Instance.new('Animation')
animation.AnimationId = "http://www.roblox.com/Asset?ID=2769812861"

local animTrack = Humanoid:LoadAnimation(animation)
animTrack.Play()

I asked a question about this earlier but I feel that I might have asked it wrong... I created an rthro rig and tried to animate it. I successfully created and uploaded the animation, but I am having issues activating it. I placed this script into the rig (no where in specific), titled "Dummy," and it isn't really working... Are there any steps I am missing? Did I write the code wrong? Does the script need to be in a different place? Any help is welcome. Thank you.

Also it might be important to note that I used this link to create this: http://wiki.roblox.com/index.php?title=Animations#Using_Animation_in_Games

Sorry, didn't see you wanted to animate the NPC. To animate the NPC it needs to have 2 things:

1. Animation
2. Humanoid

Try using this:

local humanoid = script.Parent:WaitForChild("Humanoid") --Finds the Humanoid
local animTrack = hum:LoadAnimation(script:FindFirstChildOfClass("Animation")) --Finds your Animation inside the script (FindFirstChildOfClass) (The ClassName of Animation is "Animation", so it specificly finds the Animation itself.. nothing else.)

animTrack.Looped = true --You can make it looped.
animTrack:Play() --Play the Animation

Note: This script should be a ServerScript inside your NPC. Your Animation should be inside the script and it needs to have the AnimationID.