protected void btnSearch_Click(object sender, EventArgs e)
        {
            string headID = (string)Session["loginID"];
            string deptID = deptStaffDAO.findStaffByID(headID).deptID;

            List <RequisitionByStaffCart> list = new List <RequisitionByStaffCart>();

            string ReqStaffName = ddlStaff.Text;
            string from         = txtFrom.Text;
            string to           = txtTo.Text;

            if ((from == "" || to == "") && ReqStaffName == "---Select Name---")
            {
                ClientScript.RegisterStartupScript(ClientScript.GetType(), "myscript", "<script>win.alert('Notice', 'Please input condition!');</script>");
            }

            if (ReqStaffName == "---Select Name---" && (from != "" && to != ""))
            {
                DateTime dateFrom = Convert.ToDateTime(from);
                DateTime dateTo   = Convert.ToDateTime(to);
                list = reqDAO.findRequisitionByDate(dateFrom, dateTo, deptID);
            }
            if ((from == "" || to == "") && ReqStaffName != "---Select Name---")
            {
                string ReqStaffID = deptStaffDAO.findStaffByName(ReqStaffName).staffID;
                list = reqDAO.findRequisitionByStaffID(ReqStaffID);
            }
            if (from != "" && to != "" && ReqStaffName != "---Select Name---")
            {
                DateTime dateFrom   = Convert.ToDateTime(from);
                DateTime dateTo     = Convert.ToDateTime(to);
                string   ReqStaffID = deptStaffDAO.findStaffByName(ReqStaffName).staffID;
                list = reqDAO.findRequisitionByDateAndStaffID(dateFrom, dateTo, ReqStaffID);
            }

            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();
        }
        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();
        }