void BillingEngine_EinvNodeAdding(object sender, MercatorUi.Engine.Gescom.BillingEngine.EinvNodeAddedEventArgs e)
{
MercatorUi.Engine.Gescom.BillingEngine billingEngine = (MercatorUi.Engine.Gescom.BillingEngine)sender;
if (e.Node.Name == "cac:OrderReference")
{
XmlNode n = billingEngine.EinvAddNode(e.eInvoiceEnum, e.ParentNode, "cac:InvoicePeriod");
billingEngine.EinvAddNode(e.eInvoiceEnum, n, "cbc:StartDate", Convert.ToDateTime(billingEngine.PIEDS["date_1"]));
billingEngine.EinvAddNode(e.eInvoiceEnum, n, "cbc:EndDate", Convert.ToDateTime(billingEngine.PIEDS["date_2"]));
}
}