*** Version 2.2.1 ***

Added the following features:
-----------------------------

+ Added "getHiddenField" method to YAHOO.widget.Button.


Fixed the following bugs:
-------------------------

+ Removed built-in use of the Event utility's "onAvailable" method from the
  constructor of Button and ButtonGroup as it was preventing the addition of 
  event listeners on instances created from existing markup.  Going forward 
  Button and ButtonGroup instances created from existing markup can only be 
  instantiated once their source HTML element is available in the DOM.  The 
  Button examples illustrate how this can be accomplished.

+ Modified code so that disabled Button instances no longer fire DOM events.

+ Pressing the enter key while focused on a form field whose parent form 
  contains a Button instance of type "submit" will now automatically submit 
  the form using the first Button instance of type "submit".

+ Clicking a Button instance of type="submit" will now cause the Button's 
  parent form's "submit" event to fire.

+ Modified Button CSS so that the filter used to apply alpha transparency to 
  a Button's background PNG is only used by IE 6.  The previous code was 
  enabling IE's Alpha image loader for IE 7 in Quirks mode. 

+ Fixed documentation error for "getForm" method.  


Changes:
--------

+ Made the "submitForm" method of YAHOO.widget.Button public (was 
  previously protected).  

+ Removed "init" event and corresponding "oninit" configuration attribute
  from YAHOO.widget.Button and YAHOO.widget.ButtonGroup.

+ Added the CSS class "ie6" to button.css.  This classname is append to root 
  DOM element of Button instances created with IE 6.  By default this class
  is used to apply a filter that gives alpha transparency to a Button's 
  background PNG.



*** Version 2.2.0 ***

* Button Control introduced