private void NewXmlNode(string styleName)
{
this.Node = this.Document.CreateNode("chart", "chart");
if (styleName!=null)
{
XmlAttribute xa = this.Document.CreateAttribute("style-name", "chart");
xa.Value = styleName;
this.Node.Attributes.Append(xa);
this.ChartStyle = new ChartStyle (this.Document ,styleName);
this.Styles .Add (this.ChartStyle);
}
}