/div>

<h2>Overview</h2><div class="docstring">
  <div class="discussion">
    
<p>A radio button is a tri-state button.  Normally, it is either <code>TRUE</code> or <code>FALSE</code>; a third state <code>MAYBE</code> may be set to indicate that no selection has been made yet by the user, or that the state is ambiguous. When pressed, the radio button sets its state to <code>TRUE</code> and sends a <code>SEL_COMMAND</code> message to its target, with the message data set to the state of the radio button. A 