Write a GUI application that acts as a cash register. In other words, a client brings a basket of items, their barcodes are scanned, and their total is calculated. The main window should have a menu bar with two menus Sale and Item. The Sale menu should have options New, Cancel, Finalise and Exit, and the Item menu should have options to Add and Remove. The main window should also have a toolbar (at the bottom of the window) with a toolbar button for each of these options.