Welding script not working?

Player = script.Parent.Parent

x = Instance.new("Part")
x.Size = Vector3.new(1, 3, 1)
x.TopSurface = "Smooth"
x.BottomSurface = "Smooth"
x.BrickColor = BrickColor.new("Mild Gray")
x.Reflectance = 0.3

x.Parent = c
game.Debris:AddItem(x,5)

w1 = Instance.new("Weld", c)
w1.Part0 = w1.Parent["Right Arm"]
w1.Part1 = x
w1.C1 = CFrame.fromEulerAnglesXYZ(0, 0, 0) *CFrame.new(0, 0, 0)

Is the script. I get a problem saying Players.Sarcasticly.Backpack.Script:14: attempt to call field 'Parent' (a nil value) Any help?

Note that you have to define everything, in this case what is c. Remember always define

Im Sorry, This Is Not A Valid Thing To Post!