public Object getValueAt(int rowIndex, int columnIndex) {
        PartsSalesBean bean = (PartsSalesBean) data.get(rowIndex);


        switch (columnIndex) {
            case 0:
                return bean.getPartNumber();
            case 1:
                return bean.getDescription();
            case 2:
                return String.valueOf(bean.getQuantity());
            case 3:
                return Utility.formatCurrency(bean.getUnitPrice());
            case 4:
                return Utility.formatCurrency(bean.getDiscountedPrice());
            case 5:
                return Utility.formatCurrency(bean.getNetPrice());
            case 6:
                return Utility.formatCurrency(bean.getSubtotal());
        }
        return "";
    }