title: How to insert xml data into existing xml in c#?
body: <p>i added xml file in my windows application, i want to add values to that from textbox.. 
  i used the following code,</p>
  
  <pre><code>string path = "codedata.xml";
          XmlDocument doc = new XmlDocument();
          if (!System.IO.File.Exists(path))
          {
              //Create neccessary nodes
              XmlDeclaration declaration = doc.CreateXmlDeclaration("1.0", "UTF-8", "yes");
              XmlComment comment = doc.CreateComment("This is an XML Generated File");
              doc.AppendChild(declaration);
              doc.AppendChild(comment);
          }
          else //If there is already a file
          {
              //    //Load the XML File
              doc.Load(path);
          }
  
          //Get the root element
          XmlElement root = doc.DocumentElement;
  
          XmlElement Subroot = doc.CreateElement("data");
          XmlElement Companycode = doc.CreateElement("Companycode");
          XmlElement Productcode = doc.CreateElement("Productcode");
          XmlElement Productname = doc.CreateElement("Productname");
          XmlElement Brandcode = doc.CreateElement("Brandcode");
          XmlElement Brandname = doc.CreateElement("Brandname");
  
          Companycode.InnerText = txt_companycode.Text;
          Productcode.InnerText = txt_productcode.Text;
          Productname.InnerText = txt_productname.Text;
          Brandcode.InnerText = txt_brandcode.Text;
          Brandname.InnerText = txt_brandname.Text;
  
          Subroot.AppendChild(Companycode);
          Subroot.AppendChild(Productcode);
          Subroot.AppendChild(Productname);
          Subroot.AppendChild(Brandcode);
          Subroot.AppendChild(Brandname);
          root.AppendChild(Subroot);
          doc.AppendChild(root);
  
  
          //Save the document
          doc.Save(path);
  
  
          //Show confirmation message
          MessageBox.Show("Details  added Successfully");
  </code></pre>
  
  <p>it showing error near  root.AppendChild(Subroot); can any one help me, wer i made mistake.</p>