I cant figure out why my door script won't close the door, any suggestions?

I am making a script that uses a click detector to close and open a door. I used a for loop to make the door closing/opening look more smoother. The script is fine when it comes to opening the door, however the second part of the function, which allows for the closing of the door does not work. The button color does not change and stays at green, and the door does not close.

Button = script.Parent.Button
Door  = script.Parent.Door
IsOpen = false

function clicked()
    if IsOpen == false then
        Button.BrickColor = BrickColor.Green()
        for i = 0, 1, 0.1 do
            wait()
            Door.Transparency = i
            Door.CanCollide = false
        end
        IsOpen = true
    elseif IsOpen == true then
        Button.BrickColor = BrickColor.Red()
        for i = 1, 0, 0.1 do
            wait()
            Door.Transparency = i
            Door.CanCollide = true
        end
        IsOpen = false
    end
end

Button.ClickDetector.MouseClick:connect(clicked)