Multiple Values Autocomplete

  // autocomplete on reports
	$( "#recipients" )
		// don't navigate away from the field on tab when selecting an item
		.bind( "keydown", function( event ) {
		  if ( event.keyCode === $.ui.keyCode.TAB &&
		      $( this ).data( "ui-autocomplete" ).menu.active ) {
		    event.preventDefault();
		  }
		})
		.autocomplete({
		  minLength: 0,
		  source: function( request, response ) {
		    // delegate back to autocomplete, but extract the last term
		    response( $.ui.autocomplete.filter(
		      groups, extractLast( request.term ) ) );
		  },
		  focus: function() {
		    // prevent value inserted on focus
		    return false;
		  },
		  select: function( event, ui ) {
		    var terms = split( this.value );
		    // remove the current input
		    terms.pop();
		    // add the selected item
		    terms.push( ui.item.value );
		    // add placeholder to get the comma-and-space at the end
		    terms.push( "" );
		    this.value = terms.join( ", " );
		    return false;
		  }
		});