public void ValidateCode(object sender, RoutedEventArgs e)
        {
            object context             = Utils.GetDataContext(sender);
            IEnumerable <XmlNode> data = Utils.GetXmlDataContext(context);

            if (null != data)
            {
                foreach (XmlNode node in data)
                {
                    XmlNode attr = node.SelectSingleNode("languageCode/@value");
                    if (null != attr)
                    {
                        string code = attr.Value;
                        if (2 == code.Length)
                        {
                            string threeLetter = LanguageConverter.GetThreeLetterCode(code);
                            if (null != threeLetter)
                            {
                                attr.Value = threeLetter;
                                MetadataEditorControl.UpdateDataContext(this as DependencyObject);
                            }
                        }
                    }
                    break; // just one
                }
            }
        }