Creating a button field set
A button field set is a set of buttons that all have the same width on the screen. You can use the VerticalButtonFieldSet class to align buttons vertically on a screen, and you can use the HorizontalButtonFieldSet class to align buttons horizontally on a screen. The width of the buttons can change depending on properties such as the width of the screen or the content of the buttons. By default, the buttons in a VerticalButtonFieldSet expand to the width of the largest button in the set, but you can alter this behavior by using style bits. For example, you can specify the USE_ALL_WIDTH style bit of the Field class when you create a VerticalButtonFieldSet object to direct the buttons to use the entire available width of the screen. The buttons in a HorizontalButtonFieldSet are placed in a horizontal row that fills the entire width of the screen, and the buttons are resized automatically to have equal widths.
You might use a VerticalButtonFieldSet object to make sure that a set of buttons all have the same size regardless of the content of the buttons. You might use a HorizontalButtonFieldSet object to place buttons along the top or bottom of a screen, such as confirmation or cancel buttons.