public void UpdateInvoiceDetail(InvoiceDetail invoiceDetail)
 {
     ctx.Entry(invoiceDetail).State = System.Data.Entity.EntityState.Modified;
     ctx.SaveChanges();
 }
 public void UpdateCustomer(Customer customer)
 {
     ctx.Entry(customer).State = System.Data.Entity.EntityState.Modified;
     ctx.SaveChanges();
 }