XmlDocument xDoc = new XmlDocument();
            xDoc.Load(@"D:\anandlv\xmlReading\WindowsApplication3\XMLFile1.xml");
            XmlTextReader xReader = new XmlTextReader();
            xDoc.SelectNodes(@"D:\anandlv\WindowsAppliction3\WindowsApplication3\XMLFile1.xml");
           XmlNode node;
            string sVar = node.ChildNodes[0].Attributes["num"].Value;
            XmlNodeList xN1 = xDoc.GetElementsByTagName("val1");
            XmlNodeList xN2 = xDoc.GetElementsByTagName("val2");
            MessageBox.Show(xN2.Count.ToString());
            foreach (XmlNode node in xN1)
            {
              MessageBox.Show(node.InnerText);
                foreach (XmlAttribute attr in node.Attributes)
                {
                   MessageBox.Show(attr.Name + "," + attr.Value);
               }
            }

THESE ARE THE CODE TO WRITE XML FILE

XmlTextWriter xWriter = new XmlTextWriter(@"D:\anandlv\xmlReading\WindowsApplication3\XMLFile1.xml", null);
            xWriter.WriteStartDocument();//starting document

            xWriter.WriteStartElement("values");//starting parent node
            xWriter.WriteStartElement("values1");//1st child node

            xWriter.WriteAttributeString("id", "1000");//attributes of child node
            xWriter.WriteAttributeString("name", "ABC");
            xWriter.WriteString("ISO Company");//innertext
            xWriter.WriteEndElement();
            xWriter.WriteStartElement("num");//2nd child node
            xWriter.WriteAttributeString("more", "100");
            xWriter.WriteAttributeString("less", "10");
            xWriter.WriteString("numeric");
            xWriter.WriteEndElement();
            xWriter.WriteStartElement("r", "runnnig", "");//3rd child node
            xWriter.WriteAttributeString("fast", "1000km");
            xWriter.WriteAttributeString("slow", "100km");
            xWriter.WriteString("killometers");
            xWriter.WriteEndElement() ;
            xWriter.WriteStartElement("character");
            xWriter.WriteAttributeString("char", "a");
            xWriter.WriteAttributeString("another", "b");
            xWriter.WriteEndElement();
            
            xWriter.WriteEndElement();
 xWriter.WriteEndDocument();
            xWriter.Close();