How do I make it so you can look up and down with a gun and the gun will follow?

wait()
Tool=script.Parent
CP,Torso,g=nil,nil,nil
necko=CFrame.new(0, 1, 0, -1, -0, -0, 0, 0, 1, 0, 1, 0)
getPos=function(Pos,TorsoPos)
    return Vector3.new(Pos.x,TorsoPos.y,Pos.z)
end
Turn=function(mouse,Torso,Gyro)
    g.cframe=CFrame.new(Torso.Position,getPos(mouse.Hit.p,Torso.Position))
    offset=(Torso.Position.y-mouse.Hit.p.y)/100
    mag=(Torso.Position-mouse.Hit.p).magnitude/80
    offset=offset/mag
    neck=Torso.Neck
    neck.C0=necko*CFrame.fromEulerAnglesXYZ(offset,0,0)
    arm=Torso:FindFirstChild("Right Shoulder")
    if arm~=nil then
        arm.C0=CFrame.new(1, 0.5, 0, 0, 0, 1, -6.48200512e-007, 1.00000274, 0, -1.00000274, -6.48200512e-007, 0)*CFrame.fromEulerAnglesXYZ(0,0,-offset)
    end
end

Equi=function(mouse)
    wait(.2)    
    CP=Tool.Parent
    Torso=CP.Torso
    g=Instance.new("BodyGyro")
    g.P=18000
    g.D=600
    g.maxTorque=Vector3.new(1/0,1/0,1/0)
    g.cframe=Torso.CFrame
    g.Parent=Torso
    while true do
        if Tool.Parent.className~="Model" then
            break
        end
        Turn(mouse,Torso,g)
        wait()
    end
    Torso.Neck.C0=necko
    g:Remove()
end
Tool.Equipped:connect(Equi)