fun goToFragment(view: View){
        val fmManager = supportFragmentManager
        val transaction = fmManager.beginTransaction()
        val fragment: Fragment
        when(view.tag) {
            "0" -> {
                fragment = PlayFragment.newInstance()
                isPlayModeOn = true
            }
            "1" -> {
                fragment = PracticeFragment.newInstance()
            }
            "2" -> {
                fragment = DiagramFragment.newInstance()
            }
            "3" -> {
                fragment = InstructionFragment.newInstance()
            }
            else -> {
                fragment = SettingsFragment.newInstance()
            }
        }
        fmManager.popBackStackImmediate()
        transaction.replace(R.id.mainApp, fragment).addToBackStack(null).commit()
    }