How to save Client-side Form data to Store

Hello!

I have got a Demoproject from a company. I need to do everything in client-side. I get from them a .js file what contains the data. It's okey, I can read it to a JsonStore. My problem is the next:

I need to create a form for a transaction, I have accounts and I need to manipulate them, so I need to reduce the available balance and show this transaction with the others.

Can somebody give me a code with a store with one field and a form with one textfield or any other and if you press a button, then this textfield value added to the store and the file too.

I hope somebody can help me.