Only One Decimal Point In Textbox, Using Keyascii

[Dark Light]

This is want I have at the moment.

Private Sub text1_keypress(keyascii As Integer)
        Select Case keyascii
            Case "8", "46", "48", "49", "50", "51", "52", "53", "54", "55", "56", "57", "127"
        Case Else
            keyascii = 0
        End Select
End Sub

But I only want a maximum of one decimal Point, how do I do this?