TakeDamage is not a valid member of Part ??

Hi, i don't understand why i keep getting this error. I'm trying to make a script where you deal 10 damage when touching a part.

local Main = script.Parent

Main.Touched:Connect(function(hit)
	if hit.Parent:FindFirstChild("Humanoid") then
		hit:TakeDamage(10)
	end
end)

Also the script is inside a model as you can see here: (http://i.imgur.com/Hq4jPvJ.png)

The model contains a humanoid because i want it to display a name above it.