How to fill the data into the textboxes from an xml file?

private void SearchXmlData(int selectedIndex)
{
    XmlDocument docXml = new XmlDocument();
    docXml.Load(Server.MapPath(@"App_Data\TestXmlFile.xml"));
    XmlNodeList list = docXml.DocumentElement.ChildNodes;
    XmlNode node = list.Item(selectedIndex);
    this.txtUser.Text = node["UserName"].InnerText;
    this.txtQuestion.Text = node["Question"].InnerText;
    this.txtSolution.Text = node["Solution"].InnerText;
}