protected void BindGrid()
        {
            string headID = (string)Session["loginID"];
            string deptID = deptStaffDAO.findStaffByID(headID).deptID;
            List <RequisitionByStaffCart> list = new List <RequisitionByStaffCart>();

            list = reqDAO.findRequisitionByDeptID(deptID);

            for (int i = list.Count - 1; i >= 0; i--)
            {
                RequisitionByStaffCart reqByStaffCart = new RequisitionByStaffCart();
                reqByStaffCart = list[i];
                string reqStatus = reqByStaffCart.Status;
                if (reqStatus == "pending")
                {
                    list.RemoveAt(i);
                }
            }

            GridView_ReqHistory.DataSource = list;
            GridView_ReqHistory.DataBind();
        }