I want to create a simple accounting software.

It has a main window with all the menus and other windows for making vouchers, stock, etc..

The main window is main.cpp and other files will be xyz.cpp ,etc.

How do I go about with the application ?

Lets say I click on the "Create ledger" tool button.

Then how do I link the ledger.cpp file and show the Ledger creation dialog ??