Private Function validator(x As Object, button As Object) As Integer
        Dim reg As New Regex("^[A-Za-z0-9]{1,9}$",
                   RegexOptions.None)
        Dim m As Match = reg.Match(x.Text)
        If Not m.Success Then
 
            button.Visible = False
 
        Else
            If x.Items.Count > 0 Then
                For Each item In x.Items
                    If UCase(item.ToString) = UCase(x.Text) Then
                        button.Visible = False
                        Exit For
                    Else
                        button.Visible = True
                    End If
                Next
            Else
                button.Visible = True
            End If
        End If
        Return 0
    End Function