How to retrieve Webmethod from XmlDataDocument

using System.Xml;
using System.Text;

XmlNode Node = oWebMethod.GetResults(Value);
                    DataSet dtResult = ConvertYourXmlNodeToDataSet(Node);


public static DataSet ConvertYourXmlNodeToDataSet(XmlNode xmlnodeinput)
    {
        DataSet dataset = null;
        if (xmlnodeinput != null)
        {
            XmlTextReader xtr = new XmlTextReader(xmlnodeinput.OuterXml, XmlNodeType.Element, null);
            dataset = new DataSet();
            dataset.ReadXml(xtr);
        }
        return dataset;
    }