 
             // This will create the skin and attach it
             PopUpManager.addPopUp(this, owner, modal);
-            
+
             updatePopUpPosition();
         }
-        
+
         // Change state *after* we pop up, as the skin needs to go be in the initial "closed"
-        // state while being created above in order for transitions to detect state change and play. 
+        // state while being created above in order for transitions to detect state change and play.
         _isOpen = true;
         invalidateSkinState();
         if (skin)

     *  Listeners installed during the phase after the initial activate effect
     *  is complete and before the deactive effect starts.
     */
    private function installActiveListeners():void
    {
        if (!activeListenersInstalled)
        {
            // Check for explicitHeight changes while the soft keyboard
            // effect is active (but not playing)
            addEventListener("explicitHeightChanged", explicitHeightChangedHandler);
            activeListenersInstalled = true;
        }
    }
    
    /**
     *  @private
     */
    private function uninstallActiveListeners():void
    {
        if (activeListenersInstalled)
        {
            removeEventListener("explicitHeightChanged", explicitHeightChangedHandler);
            activeListenersInstalled = false;
        }
    }
}

    {
        _marginTop = value;
    }

    //----------------------------------
    //  marginBottom
    //----------------------------------

    private var _marginBottom:Number = 0;

    /**
     *  @private
     *  Defines a margin at the bottom of the screen where the pop-up cannot be
     *  resized or moved to.
     */
    mx_internal function get softKeyboardEffectMarginBottom():Number
    {
        return _marginBottom;
    }

    /**
     *  @private
     */
