jQuery plugin to auto show/hide confirmation field

hide_confirmation.jquey.js

/*!
 * jQuery HideConfirmation Plugin
 * version: 1.0 (27-JUL-2011)
 * created by: PavelTyk https://github.com/PavelTyk
 *
 * This is a simple plugin to automatically hide confirmation fields if
 * no changes made to observed field.
 *
 * Dual licensed under the MIT and GPL licenses:
 *   http://www.opensource.org/licenses/mit-license.php
 *   http://www.gnu.org/licenses/gpl.html
 */

;(function($){

/*
  Usage Note:
  -----------
  HTML:
  <input type="text" id="email" />
  <input type="text" id="email_confirmation" />

  JavaScript:
  $(document).ready(function() {
    $('#email').hideConfirmation();
  });

  Customization:
  You can override two helper functions used to hide and show
  confirmation field:
    __hide:__ $.fn.hideConfirmation.hideConfirmationElement = function() {}
    __show:__ $.fn.hideConfirmation.showConfirmationElement

  Investigate source code to find out what is the default behavior :)
*/

  $.fn.hideConfirmation = function() {

    return $(this).each(function() {
      var element = $(this),
          confirmation_element = $('#' + element.attr('id') + '_confirmation'),
          initial_value = element.val();

      if (confirmation_element.val() == '')
        $.fn.hideConfirmation.hideConfirmationElement(confirmation_element);

      element.keyup(function(){
        if ($(this).val() == initial_value)
          $.fn.hideConfirmation.hideConfirmationElement(confirmation_element)
        else
          $.fn.hideConfirmation.showConfirmationElement(confirmation_element)
      });

    });
  };

  $.fn.hideConfirmation.hideConfirmationElement = function(element) {
    element.hide().val('').prev('label').hide()
  };

  $.fn.hideConfirmation.showConfirmationElement = function(element) {
    element.show().prev('label').show();
  };
})(jQuery);