Need help ASAP script keeps glitching/lagging why? (Read desc)

Note: I DON'T copy script I make them my self if there's any proof of me copying a script show me. Anyways, I was trying to do is when a player mouse click the button the brick will disappear.

function on()
 isOn = true
 script.Parent.Transparency = 0
 script.Parent.CanCollide = true 
end

function off()
 isOn = false
 script.Parent.Transparency = .5 
 script.Parent.CanCollide = false 
end

function onClicked()
 
 if isOn == true then off() else on() end

end

script.Parent.ClickDetector.MouseClick:connect(onClicked)

on()