private void Frm_onAdd(object sender, EventArgs e)
        {
            Bill       bill = BillDAL.Instance.GetBillByID(BillDAL.Instance.GetMAXIDBill());
            ItemInBill item = new ItemInBill(bill.ID, bill.CheckOut, bill.StaffID, StaffDAL.Instance.GetNamebyID(bill.StaffID), bill.NOTE, Math.Abs(bill.Total), true);

            this.flowLayoutPanelBill.Controls.Add(item);
            this.SetBackGround();
            this.SizeChange();
            this.cbSearch.SelectedIndex = 0;
            this.SearchAllNote();
        }
        private void LoadBill()
        {
            flowLayoutPanelBill.Controls.Clear();
            List <Bill> bills = BillDAL.Instance.LoadBill();

            Income = Spend = 0;
            bool setcolor = true;

            foreach (Bill bill in bills)
            {
                if (setcolor)
                {
                    setcolor = false;
                }
                else
                {
                    setcolor = true;
                }

                string StaffName = StaffDAL.Instance.GetNamebyID(bill.StaffID);

                ItemInBill item = new ItemInBill(bill.ID, bill.CheckOut, bill.StaffID, StaffName, bill.NOTE, Math.Abs(bill.Total), setcolor);
                if (bill.Total < 0)
                {
                    Spend += bill.Total;
                }
                else
                {
                    Income += bill.Total;
                }
                item.Tag = bill;
                flowLayoutPanelBill.Controls.Add(item);
            }
            Spend *= -1;
            lbTotalIncome.Text = string.Format("{0:n0}", Income).ToString();
            lbTotalSpend.Text  = string.Format("{0:n0}", Spend).ToString();
            SizeChange();
        }