Auto-Tabbing

I use Storyline to do a lot of software simulation. I need the ability to trigger the next entry field automatically when the user hits the character limit of the pervious field without having to press a button to remove focus from one and set focus to the other. I've been looking for this for years and the only solutions I can find are javascript, and I don't understand how to make it work. I know other people also want this feature. Please!