Sub txtX_TextChanged (Old As String, New As String)
If txtX.Text = "" Then
Return
Else
Dim chrtolookat As String = txtX.Text.CharAt(txtX.Text.Length - 1)
Select chrtolookat
Case "0","1","2","3","4","5","6","7","8","9"
Return
Case "."
If Old.Contains(".") Then
txtX.Text = txtX.Text.SubString2(0,txtX.Text.Length - 1)
txtX.SetSelection(txtX.Text.Length,txtX.Text.Length)
Else
Return
End If
Case Else
txtX.Text = txtX.Text.SubString2(0,txtX.Text.Length - 1)
txtX.SetSelection(txtX.Text.Length,txtX.Text.Length)
End Select
End If
End Sub