XmlDocument xmlDoc = new XmlDocument();

                if (!File.Exists(xmlFileName))

                {

                    return string.Empty;

                }

                xmlDoc.Load(xmlFileName);

                XmlNodeList nodes = xmlDoc.SelectNodes(keyPath);

                foreach (XmlNode node in nodes)

                {

                    foreach (XmlNode childNode in node.ChildNodes)

                    {

                        if (childNode.Name == keyName.ToUpper())

                        {

                            string dataValue = childNode.InnerText;

                            return dataValue;

                        }

                    }

                }