Moving frame help?

I have a frame in startergui and in the frame I have a imagelabel. So what this does it makes the frame move from left to right and continuing. I want it to hit the left side of the screen and not come back.

Startposition=script.Parent.Position

while true do
    local RightBorder=script.Parent.AbsolutePosition.X+script.Parent.AbsoluteSize.X
    if RightBorder<=0 then
        script.Parent.Position=Startposition
    else
        script.Parent.Position=script.Parent.Position-UDim2.new(0.005,0,0,0)
    end
    wait()
end