protected void btnLease_Click(object sender, EventArgs e)
        {
            Slip_Id = DockSlipControl.SlipId; //get slipid from the usercontrol
            if (Session["CustomerID"] != null)
            {
                custId = (int)Session["customerID"];
            }
            var leaseSlip = new Lease
            {
                SlipID     = Slip_Id,
                CustomerID = custId
            };

            //pass the leaseSlip object to the manager for inserting
            DockManager.Add(leaseSlip);

            showLeasedSlips();           //show leased slips

            DockSlipControl.loadSlips(); //refresh the slip dorpdown
        }