     
     public func changeLeftViewController(leftViewController: UIViewController, closeLeft:Bool) {
         
-        removeViewController(leftViewController)
+        removeViewController(self.leftViewController)
         self.leftViewController = leftViewController
         setUpViewController(leftContainerView, targetViewController: leftViewController)
         if closeLeft {

    }
    
    public func changeRightViewController(rightViewController: UIViewController, closeRight:Bool) {
        removeViewController(rightViewController)
        self.rightViewController = rightViewController;
        setUpViewController(rightContainerView, targetViewController: rightViewController)
        if closeRight {

    
    public func changeMainViewController(mainViewController: UIViewController,  close: Bool) {
        
        removeViewController(self.mainViewController)
        self.mainViewController = mainViewController
        setUpViewController(mainContainerView, targetViewController: mainViewController)
        if (close) {
