c# - XML file - load xml, modify xml, save xml - HOW!!

[AnfieldRoar]

Hi, if I load an XML file, then modify a value, then try to save it I get an exception, access denied error. I've tried everything - help please????

For example:

XmlReaderSettings settings = new XmlReaderSettings();
settings.CloseInput = true; // should close immediately now
XmlReader reader = XmlReader.Create(filename, settings);
XmlDocument doc = new XmlDocument();
doc.Load(reader);
reader.Close();

XmlNodeList list = doc.GetElementsByTagName("bookname");
list.Item(0).InnerText = "new name";

doc.Save(filename);


Many thanks...