I can't get a flashing light to turn on when clicked?

As you may know from my previous post I am trying to make a game with cars in but one problem I am "suffering" from is that I am using a light where when you click it should flash.

while true do
script.Parent.ClickDetector.MouseClick:Connect(function()
script.Parent.Material = ("Neon")
wait(.5)
script.Parent.Material = ("Plastic")
end

please help me!

hierachy: Blue ClickDetector Script

as simplified

Okay...let me start with problem one you have missing ends there should be an end). Problem 2 switch while true do and the function if you do that you are binding a function to a loop which isn't a good idea.So this it how it should look like.

script.Parent.ClickDetector.MouseClick:Connect(function()
while true do
script.Parent.Material = ("Neon")
wait(.5)
script.Parent.Material = ("Plastic")
end
end)

If you don't understand why it didn't work before ask in comments.