    <p>Instances of NSButton include pushbuttons with either text or
    image labels (or both), checkboxes, and radio buttons. In order to
    make a text pushbutton, we need to tell our button to use a
    button-type of <code>NSMomentaryPushInButton</code>, an image
    position of <code>NSNoImage</code>, and a border style
    of <code>NSRoundedBezelStyle</code>. These style options are
    represented by Cocoa constants.</p>
    
    <p>We also need to give the button a frame rectangle that defines
   