      *  @private
      *  Reference to the selected radio button.
      */
-    private var _selection:FxRadioButton;
+    private var _selection:RadioButton;
 
     [Bindable("change")]
     [Bindable("valueCommit")]

    /**
     *  @private
     */
    mx_internal function setSelection(value:FxRadioButton, fireChange:Boolean = true):void
    {
        if (_selection == value)
            return;


    /**
     *  @private
     *  The document containing a reference to this RadioButtonGroup.
     */
    private var document:IFlexDisplayObject;

    /**
     *  @private
     *  An Array of the RadioButtons that belong to this group.
     */
    private var radioButtons:Array /* of RadioButton */ = [];

    /**
     *  @private
