Topic: Adding a new field in Direct Sales Invoice page

how to adding a new field, Part code field after Item Code field?
I can't understand in line sales_items_list_cells(null,'stock_id', null, false, true);
That script fusing Item Code and Item Description, it can't inseparable.

Re: Adding a new field in Direct Sales Invoice page

The file includes/ui/ui_lists.inc has:

function sales_items_list_cells($label, $name, $selected_id=null, $all_option=false, $submit_on_change=false, $editkey=false)
{
    if ($editkey)
        set_editor('item', $name, $editkey);

    if ($label != null)
        echo "<td>$label</td>\n";
    echo sales_items_list($name, $selected_id, $all_option, $submit_on_change,
        '', array('cells'=>true));
}

The file sales/includes/ui/sales_order_ui.inc uses it in:

    else    // prepare new line
    {
        sales_items_list_cells(null,'stock_id', null, false, true, true);
        if (list_updated('stock_id')) {
                $Ajax->activate('price');
                $Ajax->activate('units');
                $Ajax->activate('qty');
                $Ajax->activate('line_total');
        }