The action associated with a button should be visible to the user and should take place immediately. The label of a button should be unambiguous. Usually, it should be a verb that describes the effect of pushing the button, though another label—such as OK or Options—is acceptable if its meaning is clear. For buttons that call other dialog boxes or hide the current dialog box, see Nesting Dialog Boxes and Closing a Dialog Box for User Selection.
Buttons in a column should be the same width. In other cases, buttons should have a fixed width (either fixed_width =true;, or children_fixed_width =true;) in their common parent cluster.
