How do I write to an XML file on an ASP.net page in C#?

[Tom]

I've tried using System.Xml.XmlTextWriter but I couldn't get permission for the page to write to the XML file. Right clicking on the file and changing the security options doesn't work either as there isn't an ASP.NET user and I've tried allowing every single other user to write to the file but still the the didn't have permission to write to the XML file.