用DataSet修改WebConfig

今天看到一招用DataSet修改WebConfig，真是简洁明了，一同分享

     public   void  write()
         {
            string newValue= this.TextBox1.Text;
            DataSet ds = new DataSet();
            ds.ReadXml(Server.MapPath("")+"/web.config");
            ds.Tables[1].Rows[0][1] = key1;
            ds.AcceptChanges();
            ds.WriteXml(Server.MapPath("")+"/web.config");
            ds.Dispose();
            
        }