private fun showContentPanel(show : Boolean, panel : Node) {

        if( show && !innerContainer.items.contains(panel) ) {

            panel.opacity = 0.0

            innerContainer.items.add( panel )

            val ft = FadeTransition(Duration.millis(400.0), panel)
            ft.fromValue = 0.0
            ft.toValue = 1.0
            ft.cycleCount = 1
            ft.isAutoReverse = false
            ft.play()

        } else if( !show && innerContainer.items.contains(panel) ) {

            val ft = FadeTransition(Duration.millis(300.0), panel)
            ft.fromValue = 1.0
            ft.toValue = 0.1
            ft.cycleCount = 1
            ft.isAutoReverse = false
            ft.play()

            ft.setOnFinished { e -> innerContainer.items.remove(panel) }
        }
    }