protected virtual void RenderDocumentStart(HtmlTextWriter writer)
{
if (writer == null)
throw new ArgumentNullException("writer");
writer.WriteLine("<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">");
writer.AddAttribute("xmlns", "http://www.w3.org/1999/xhtml");
writer.RenderBeginTag(HtmlTextWriterTag.Html); // <html>
writer.RenderBeginTag(HtmlTextWriterTag.Head); // <head>
RenderHead(writer);
writer.RenderEndTag(); // </head>
writer.WriteLine();
writer.RenderBeginTag(HtmlTextWriterTag.Body); // <body>
}