Why won't this thing work?

function changeMove()
	if MoveNum == 1 then
		MoveNum = MoveNum + 1
		Move1()
	elseif MoveNum == 2 then
		MoveNum = MoveNum + 1
		Move2()
	elseif MoveNum == 3 then
		MoveNum = MoveNum + 1
		Move3()
	elseif MoveNum == 4 then
		MoveNum = 1		
		Move4()
	end
end

Error: attempt to call global 'Move1' (a userdata value) Thats the only error, strangely. Also, the function runs on a click event.