To have buttons on the screen only

have a look at my tutorial

I have created a petty cash button (Cash Out) that only shows on the POS screen if a ticket has not been created, this runs through accounts, where you can then go to the petty cash account and balance this figure every day against your cash out receipts.

You could use my petty cash (cash out) rules and actions to create a reverse system for Cash In and duplicate it for Bank In

ive modified my system slightly from when i did this tutorial but the basics are the same, have a look and there should be a database tools file you can download so you can have a play and look a the rules and actions to see how it works

Dont for get to backup first