protected void grdCostsExceptions_RowDeleting(object sender, GridViewDeleteEventArgs e)
        {
            // Costs Exceptions Gridview, if the gridview is edition mode
            if (grdCostsExceptions.EditIndex >= 0)
            {
                grdCostsExceptions.UpdateRow(grdCostsExceptions.EditIndex, true);
            }

            // Delete Cost Exceptions
            int costId = (int)e.Keys["CostID"];
            int refId = (int)e.Keys["RefID"];
            MaterialsInformationCostHistoryExceptionsInformation model = new MaterialsInformationCostHistoryExceptionsInformation(materialsInformationTDS);

            // Delete cost exception
            model.Delete(costId, refId);

            grdCostsExceptions.DataBind();
            grdCosts.DataBind();

            // Store dataset
            Session["materialsInformationTDS"] = materialsInformationTDS;
        }