Is it possible to make a one way script?

So basically, I have a goal-line technology system that is in BETA, I'm testing it out, it will make a sound and message saying "Goal!" when the ball goes over the line, then the message SHOULD get deleted, but when it gets deleted, another message get's created when the ball bounces back out from the back of goal, can you fix this?

Script 1:

script.Parent.Touched:connect(function(otherPart)
  if otherPart.Name == "TPS" or otherPart.Name == "Ball" then
        if script.Parent.Size.y <5 and script.Parent.Size.x <5 and script.Parent.Size.z <5 then
            script.Parent.Boing.Pitch = 1
        end
        if script.Parent.Size.y >4 and script.Parent.Size.y <9 and script.Parent.Size.x >4 and script.Parent.Size.x <9 and script.Parent.Size.z >4 and script.Parent.Size.z <9 then
            script.Parent.Boing.Pitch = 0.8
        end
        if script.Parent.Size.y >8 and script.Parent.Size.y <13 and script.Parent.Size.x >8 and script.Parent.Size.x <13 and script.Parent.Size.z >8 and script.Parent.Size.z <13 then
            script.Parent.Boing.Pitch = 0.6
        end
        if script.Parent.Size.y >12 and script.Parent.Size.x >12 and script.Parent.Size.z >12 then
            script.Parent.Boing.Pitch = 0.4
        end
        script.Parent.Goal:Play()
end
end)

Script 2:

script.Parent.Touched:connect(function(otherPart)
    if otherPart.Name == "TPS" or otherPart.Name == "Ball" then
        m = Instance.new("Message")
        m.Parent = Workspace
        m.Text = "Goal!"
        wait(4)
        m:Destroy()
    end
end)

If you want too test the system, come too my place, my usernames is iJava7, it's called "Goal-Line Technology - BETA", I'm currently there and updating it if you want too try it out and fix it.