Write XML File in ASP.Net

using System.Xml;
using System.Text;

protected void Page_Load(object sender, EventArgs e)
{
XmlTextWriter writer = new XmlTextWriter(Server.MapPath("refer.xml"), Encoding.UTF8);
writer.WriteStartDocument();
writer.WriteStartElement("userinfo");
writer.WriteStartElement("browserinfo");
if (Request.UrlReferrer == null)
{
writer.WriteElementString("urlreferrer", "none");
}
else
{
writer.WriteElementString("urlreferrer", Request.UrlReferrer.PathAndQuery);
}

writer.WriteElementString("useragent", Request.UserAgent);
writer.WriteEndElement();
writer.WriteStartElement("visitinfo");
writer.WriteAttributeString("timevisited", DateTime.Now.ToString());
writer.WriteStartElement("ip", Request.UserHostAddress);
writer.WriteStartElement("rawURL", Request.RawUrl);
writer.WriteEndElement();
writer.WriteEndElement();
writer.WriteEndDocument();
writer.Close();

}