Writing XML dynamically

string xmlFile = Server.MapPath("UserControl.xml");
System.Xml.XmlTextWriter writer = new System.Xml.XmlTextWriter(xmlFile, null);
writer.WriteStartDocument();
writer.Formatting = Formatting.Indented;
writer.WriteStartElement("InputValue");


for (int i = 0; i < 3; i++)
{

writer.WriteAttributeString(i.ToString(),i.ToString());
//writer.WriteElementString(i.ToString(), i.ToString());
}
writer.WriteEndElement();
writer.Close();