private void BtnNewInvoice_Click(object sender, RoutedEventArgs e)
{
try{
clsMainLogic.Invoice newInvoice = controller.createNewInvoice();
setCurrentInvoice(newInvoice);
}
catch (Exception ex) {
HandleError(MethodInfo.GetCurrentMethod().DeclaringType.Name,
MethodInfo.GetCurrentMethod().Name, ex.Message);
}
}