public List <Invoice> returnInvoiceListOrderByInvoiceNumber()
{
List <Invoice> lst = new InvoiceDataSource().returnInvoiceList();
List <Invoice> SortedList = lst.OrderBy(o => o.InvoiceNumber).ToList();
return(SortedList);
}
public List <Invoice> returnInvoiceListOrderByStaffName()
{
List <Invoice> lst = new InvoiceDataSource().returnInvoiceList();
List <Invoice> SortedList = lst.OrderBy(o => o.Admin).ToList();
return(SortedList);
}