void AddNewRelationship(int res_number, string res_id, string res_type)
{
Dictionary <string, string> attrs = new Dictionary <string, string>();
attrs["Id"] = res_id;
attrs["Type"] = res_type;
attrs["Target"] = "worksheets/sheet" + res_number.ToString() + ".xml";
XmlElement relships = xml_wb_rels.FindFirstNode("Relationships", new Dictionary <string, string>());
xml_wb_rels.CreateElement("Relationship", attrs, String.Empty, relships);
xml_wb_rels.Document.InnerXml = xml_wb_rels.Document.InnerXml.Replace("xmlns=\"\"", String.Empty);
xml_wb_rels.SaveDocument(temp_path + "\\xl\\_rels\\workbook.xml.rels");
}
