Программирование разветвляющихся вычислительных процессов - VB

Option Explicit
Dim Y As Double, X As Double
Public Function CubeRoot(X As Double) As Double
 CubeRoot = 10 ^ ((Log(Abs(X)) / Log(10)) / 3)
End Function
Private Sub Command1_Click()
  X = InputBox("X =", , -0.8)
  Select Case X
  Case Is <= -2
    Y = Abs(X - 8)
  Case Is <= 0 
    Y = Tan(X + 1)
  Case Is > 0
    Y = CubeRoot(X - 1)
  End Select
   MsgBox (" Y =" & Y)
End Sub