how to run a javascript function before saving record?

I have never publicly published the Save & Do technique because it would only generate a flood of questions from users who did not understand it (it was somewhat invasive of QuickBase's code). I have however published an improvement to the original Save & Do technique called the Save and Scooby Do technique which you can read about here:

Save and Scooby Do
https://haversineconsulting.quickbase.com/db/bgcwm2m4g?a=dr&rid=465
https://haversineconsulting.quickbase.com/db/bgcwm2m4g?a=dr&rid=467