xsl:include throws a file not found exception

Hello, I am trying to load an xsl file which has a bunch of xsl:include statements, into an xmldocument to transform an xml. XmlDocument docXSLT = new XmlDocument(); docXSLT.Load(HttpContext.Current.Server.MapPath("../Assignment/xslt/TreeViewXMLToAssignmentXML.xslt")); string strReturnXML = oHelper.Transform(docXSLT.OuterXml.ToString(), rtvSelectedTree.GetXml()); the xslt looks like this ... I get an exception when loading the xsl saying could not find file 'C:\\Program Files\\Microsoft Visual Studio 9.0\\Common7\\IDE\\AppendTreeView.xslt. Any ideas how i could have the xsl includes point to the root of the parent xslt?? thanks much, Chandana ...