how can i stop a script from running more than once before it completely executes?

i have a script that detects chat input (the word "start"), but if you type start before the script finishes, it executes another time, is it possible to avoid the script from executing again if it hasn't already finished running?

You can check for when the chat input happens and do the following:

if Boolean == true then return end
Boolean = true

And put this on line one, or any available line at the beginning of your script

local Boolean = false

Also known as a debounce