this Script can't find screen gui that cleary exsists?

Messages = {"Hi!","This is Testing!"}

while true do
    wait(0.1)
    for i =1, #Messages do
        for _,plr in pairs(game.Players:GetPlayers()) do
        plr.PlayerGui.SCRN.Message.TextLabel.Text = Messages[i]
        plr.PlayerGui.SCRN.Message.TextLabel:TweenPosition(UDim2.new(-1, 0, 0.5, -2), "Out", "Linear", 10)
        wait(10)
        plr.PlayerGui.SCRN.Message.TextLabel.Position =  UDim2.new(1,0,0.5,-2)
    end
    end


end

This is a very simple script that displays a messages from a table on a text label and moves it accross the screen.

The problem is and line 7 and 8. It keeps saying SCRN is not apart of player gui (Scrn is a screen gui). I used wait for child, and never found it. What is going on!!!! Spellign and everything is right