Associating JS Variables to In-Game Variables

[NatuElChido]

Hello Everyone, I have a little problem.
You see, Im making a Casino in a city-like Town, for this, I find a really cool Script:
This script is very nice, it actually makes a full customizable slot machine, this is what i came out for the mine.

Spoiler

Ah, yeah, as you can tell, is in Spanish, that explains my broken english lmao

But I have some issues:
The most important, this Script uses a Chip system (In my game, they are call Stellas), the chips can be buy with money, but the chips cannot be exchange for gold, items, ect.
Another problem, the Chip counter can hit negatives, this isn't that bad because it's a casino, so having a debt with the casino can trigger some events, like, guards throwing you of the casino or some hitman chassing you.
But as you can tell, all of this thinks can be fixed if I could store the number of chips in an In-game Variable.
I'm not very familiar with JS, but I have programming knowledge, so feel free to be as especific as you want.
How can I do this?
If you need to analize the code, I will put it in a reply, to not make this post very bulky.

BTW: The creator of this script doesn't know how to do it aparently ( actually, he doesn't want to do it), this is one of those cases of old scripts that haven't recive support since launch.

Thanks everyone for reading.

 

[NatuElChido]

This are the codes.

 

[ozubon]

There had to be done a little editing so I sent you a PM if you want to try it out.

 

[insani1022]

Would also love to get this plugin to exchange chips for money or items. PM me if you figure it out. Thank you.