.Net 1.1 Compliant XSLT transform

[Actionscript Question...]

Can anyone tell me what

private XmlReader transformXml(string _xmlfilename)
{
HttpContext Context = HttpContext.Current;
XslTransform xslt = new XslTransform();
string appPath = Context.Request.ServerVariables["APPL_PHYSICAL_PATH"].ToString();
xslt.Load(appPath+"\\xml\\"+ xslFile);
XPathDocument xpathDoc = new XPathDocument(_xmlfilename);
return xslt.Transform(xpathDoc,null);
}

should be to not give me obsolete messages. The xml file is local, and
trusted, and I don't see how I can add a relevent XMLResolver.

Any ideas?

TIA