clone of Scott González' jQuery UI autocomplete html extensionn - with className support added

jquery.ui.autocomplete.html.js

/*
 * jQuery UI Autocomplete HTML Extension
 *
 * Copyright 2010, Scott González (http://scottgonzalez.com)
 * Dual licensed under the MIT or GPL Version 2 licenses.
 *
 * http://github.com/scottgonzalez/jquery-ui-extensions
 */
(function( $ ) {

  var proto = $.ui.autocomplete.prototype,
      initSource = proto._initSource;

  function filter( array, term ) {
      var matcher = new RegExp( $.ui.autocomplete.escapeRegex(term), 'i' );
      return $.grep( array, function(value) {
          return matcher.test( $( '<div/>' ).html( value.label || value.value || value ).text() );
        });
    }

  $.extend( proto, {
      _initSource: function() {
        if ( this.options.html  &&  $.isArray(this.options.source) )
        {
          this.source = function( request, response ) {
              response( filter( this.options.source, request.term ) );
            };
        }
        else
        {
          initSource.call( this );
        }
      },

      _renderItem: function( ul, item) {
          return $( '<li><a/></li>' )
              .data( "item.autocomplete", item )
              .find( '<a/>' )
                   .addClass( item.className )
                   [ this.options.html ? "html" : "text" ]( item.label )
              .end()
              .appendTo( ul );
        }
    });

})( jQuery );

Hi, I am using your script, in my Drupal page. I configured my template.php file to be including your script, under the correct path. But when I load my drupal page, I get the error: jquery.ui.autocomplete.html.js:11 Uncaught TypeError: Cannot read property 'autocomplete' of undefined. could you give me some insight on the above? Thank you in advance!