Read config file using XML reader

The best way is to use System.Configuration.ConfigurationManager.AppSettings; to retrive values of webconfig but from xml reader you can also do that:

private void loadConfig()
        {

            XmlDocument xdoc = new XmlDocument();
            xdoc.Load( Server.MapPath("~/") + "web.config");
            XmlNode  xnodes = xdoc.SelectSingleNode ("/configuration/appSettings");

                foreach (XmlNode xnn in xnodes .ChildNodes)
                {
                    ListBox1.Items.Add(xnn.Attributes[0].Value  + " = " + xnn.Attributes[1].Value );
                }              

        }