private void button3_Click(object sender, EventArgs e) { //new XPathDocument XPathDocument doc = new XPathDocument("books.xml"); //new XslTransform XslCompiledTransform trans = new XslCompiledTransform(); trans.Load("booksarg.xsl"); //new XmlTextWriter since we are creating a new xml document XmlWriter xw = new XmlTextWriter("argSample.xml", null); //create the XslArgumentList and new BookUtils object XsltArgumentList argBook = new XsltArgumentList(); BookUtils bu = new BookUtils(); //this tells the argumentlist about BookUtils argBook.AddExtensionObject("urn:XslSample", bu); //new XPathNavigator XPathNavigator nav = doc.CreateNavigator(); //do the transform trans.Transform(nav, argBook, xw); xw.Close(); webBrowser1.Navigate(AppDomain.CurrentDomain.BaseDirectory + "argSample.xml"); }