[SOLVED] Easier way to see if the user has changed something in textbox?

So right now I have this:

code = script.Parent.Code.Value
error = script.Parent.Error.Visible

while true do
if script.Parent.Text == code then
teleportPlayer()
else
error = true
wait(5)
error = false
end
end

Having a loop constantly running is a little much I think, also my server gets laggy when I have too many loops constantly going soooo, how do I make this easier?