Cant get player mouse. But I defined it. Is this correct? [Unsolved]

Script works, but it's telling me that "18:20:36.041 - Players.Player1.Backpack.Plane.Main:46: attempt to index global 'mouse' (a nil value)" When I Just defined it...

wait(0.1)	-- Yes, this is needed. If it's not here, the plane will only work once.
local player = script.Parent.Parent.Parent
local mouseSave
local maxBank = 90
local gyro = script.Parent.Parent.Parent.Character.Real.Main.Gyro

function fly(m)	-- Main function that controls all of the flying stuff. Very messy.
				inputService = game:GetService("UserInputService")

SPEED =0
while true do
	wait()
local enabled = true
Player = script.Parent.Parent.Parent
--Player:WaitForDataReady()
mouse = Player:GetMouse()		----RIGHT HERE D:
function onKeyDown(key)
if not enabled then return end
enabled = false
	Key = key:lower()
	if key == "w" then
		
		
			SPEED = SPEED +1
			print(SPEED)
		local main = script.Parent.Parent.Parent.Character.Real.Main
		local move = script.Parent.Parent.Parent.Character.Real.Main.Move
			move.velocity = (main.CFrame.lookVector + main.CFrame.lookVector*SPEED)		-- Set speed to aircraft
			
		local bank = ((((m.ViewSizeX/2)-m.X)/(m.ViewSizeX/2))*maxBank)	-- My special equation to calculate the banking of the plane. It's pretty simple actually
		bank = (bank < -maxBank and -maxBank or bank > maxBank and maxBank or bank)
			gyro.maxTorque = Vector3.new(math.huge,math.huge,math.huge)
			gyro.cframe = (m.Hit*CFrame.Angles(0,0,math.rad(bank)))

		
		
		end
		end
enabled = true
end
end

		
		
	mouse.KeyDown:connect(onKeyDown)		
	
		
		
		
		
		
script.Parent.Selected:connect(function(m)	-- Initial setup
	mouseSave = m
	game.Workspace.CurrentCamera.CameraType = Enum.CameraType.Attach
	m.Icon = "http://www.roblox.com/asset/?id=48801855"	-- Mouse icon used in Perilous Skies
	delay(0,function() fly(m) end)	-- Basically a coroutine
end)

To make it easier do something like this

local player = game.Players.LocalPlayer --saves you alot of time by not doing "script.Parent.Parent" and less errors
local mouse = player:GetMouse()

im assuming you're doing this in a local script, right?

Example

local player = game.Players.LocalPlayer
local mouse = player:GetMouse()

function fly()
	onKeyDown()
end

function onKeydown(key)
	if key == "w" then
		--while loop inside
	end --or something similar like this
end

mouse.KeyDown:connect(onKeyDown)