How can you make a BodyForce change as the lookvector changes?

If I put a body force in the direction of the lookvector it is fine, until the block is rotated, in which the body force is still applied in the direction of the initial lookvector, and the block is facing another way, how can I get around this?

Script1:

Player = game.Players.LocalPlayer
mouse = Player:GetMouse()
open = false
wait(2)
PlayerPart = game.Workspace[Player.Name .. "'s-part"]

mouse.KeyDown:connect(function(key)
    if key:lower() == "w" then
        script.Wheld.Value = true

    elseif key:lower() == "a" then
        print"a"
        bodyrot = PlayerPart.BodyAngularVelocity
        bodyrot.angularvelocity = Vector3.new(0 , 2 , 0)
    elseif key:lower() == "d" then
        bodyrot.angularvelocity = Vector3.new(0 , -2, 0)
    end
end)

mouse.KeyUp:connect(function(key)
    if key:lower() == "w" then
        script.Wheld.Value = false
    elseif key:lower() == "a" or key:lower() == "d" then
        bodyrot.angularvelocity = Vector3.new(0 , 0 , 0)
    end 
end)

Script2:

Player = game.Players.LocalPlayer
mouse = Player:GetMouse()
open = false
wait(2)
PlayerPart = game.Workspace[Player.Name .. "'s-part"]
bodyfor = PlayerPart.BodyForceForwards

wheld = script.Parent.Main.Wheld
wheld.Changed:connect(function()
    if wheld == true then
        repeat bodyfor.Force = PlayerPart.CFrame.lookVector * 50 until wheld == false
    elseif wheld == false then
        bodyfor.Force = Vector3.new(0,0,0)
    end
end)

Wheld is a Boolean which is a parent of script1. Thank you.