The main APPX title bar, located at the very top of your screen, contains three buttons at the extreme right that can be used to perform standard Windows functions. These buttons, from left to right, minimize, maximize, and close your APPX window and end your APPX session.
Subordinate title bars for other APPX windows and overlays contain three buttons at the far right that can be used to display help, save changes to the current record and move forward to the next, or to return to the previous screen or menu.
You can select the 
or HELP button while positioned anywhere on a screen to receive an online description of any process that can be invoked from the screen below, or to display detailed information about a field that appears on a data entry screen. To display this description, click HELP then click the desired option button or field. When finished reading the help text, select the 
or 
button on the help overlay's title bar to remove the help overlay.
The button is also referred to as ENTER. Selecting this button generally validates and saves any data entry you have performed on the current screen and moves you to the next record in a file, or the next screen or overlay in a series. It can be used interchangeably with the ENTER or RETURN key on your keyboard.
The or END button, when selected, ends the current process and “takes you back” to the previous process. For example, in an order/line item input process, if you select END from the line item screen, you will return to the order screen; if you select END from the order screen, you will return to the menu that you selected the order/line item input process from. Normally, if you end a menu process, you return to the previous menu process (if one exists) and, if you select END from your initial menu, you exit APPX. The F8 key performs the same function as the button.