How can i make this go up?

local Player = game.Players.LocalPlayer
local plrMouse = Player:GetMouse()

plrMouse .KeyDown:connect(function(key)
key = key:lower()
if key == 'w' then
script.Parent.Posistion = UDim2.new() -- this part im kinda confuse to make it go up a little
end
end)