...
function clear_data()
{
    unset($_POST['long_description']);
    unset($_POST['description']);
    unset($_POST['category_id']);
    unset($_POST['tax_type_id']);
    unset($_POST['units']);
    unset($_POST['mb_flag']);
    unset($_POST['NewStockID']);
    unset($_POST['dimension_id']);
    unset($_POST['dimension2_id']);
    unset($_POST['no_sale']);
    unset($_POST['no_purchase']);
    unset($_POST['depreciation_method']);
    unset($_POST['depreciation_rate']);
    unset($_POST['depreciation_factor']);
    unset($_POST['depreciation_start']);
    unset($_POST['weight']);
    unset($_POST['weight_uom']);
    unset($_POST['volume']);
    unset($_POST['volume_uom']);
}
//------------------------------------------------------------------------------------
if (isset($_POST['addupdate'])) 
{
    $input_error = 0;
    if ($upload_file == 'No')
        $input_error = 1;
    if (strlen($_POST['description']) == 0) 
    {
        $input_error = 1;
        display_error( _('The item name must be entered.'));
        set_focus('description');
    } 
    elseif (strlen($_POST['NewStockID']) == 0) 
    {
        $input_error = 1;
        display_error( _('The item code cannot be empty'));
        set_focus('NewStockID');
    }
    elseif (strstr($_POST['NewStockID'], " ") || strstr($_POST['NewStockID'],"'") || 
        strstr($_POST['NewStockID'], "+") || strstr($_POST['NewStockID'], "\"") || 
        strstr($_POST['NewStockID'], "&") || strstr($_POST['NewStockID'], "\t")) 
    {
        $input_error = 1;
        display_error( _('The item code cannot contain any of the following characters -  & + OR a space OR quotes'));
        set_focus('NewStockID');
    }
    elseif ($new_item && db_num_rows(get_item_kit($_POST['NewStockID'])))
    {
              $input_error = 1;
              display_error( _("This item code is already assigned to stock item or sale kit."));
            set_focus('NewStockID');
    }
    
  if (get_post('fixed_asset')) {
    if ($_POST['depreciation_rate'] > 100) {
      $_POST['depreciation_rate'] = 100;
    }
    elseif ($_POST['depreciation_rate'] < 0) {
      $_POST['depreciation_rate'] = 0;
    }
    $move_row = get_fixed_asset_move($_POST['NewStockID'], ST_SUPPRECEIVE);
    if (isset($_POST['depreciation_start']) && strtotime($_POST['depreciation_start']) < strtotime($move_row['tran_date'])) {
      display_warning(_('The depracation cannot start before the fixed asset purchase date'));
    }
  }
    
    if ($input_error != 1)
    {
        if (check_value('del_image'))
        {
            $filename = company_path().'/images/'.item_img_name($_POST['NewStockID']).".jpg";
            if (file_exists($filename))
                unlink($filename);
        }
        
        if (!$new_item) 
        { /*so its an existing one */
            update_item($_POST['NewStockID'], $_POST['description'],
                $_POST['long_description'], $_POST['category_id'], 
                $_POST['tax_type_id'], get_post('units'),
                get_post('fixed_asset') ? 'F' : get_post('mb_flag'), $_POST['sales_account'],
                $_POST['inventory_account'], $_POST['cogs_account'],
                $_POST['adjustment_account'], $_POST['wip_account'], 
                $_POST['dimension_id'], $_POST['dimension2_id'],
                check_value('no_sale'), check_value('editable'), check_value('no_purchase'),
                get_post('depreciation_method'), input_num('depreciation_rate'), input_num('depreciation_factor'), get_post('depreciation_start'),
                get_post('fa_class_id'),  input_num("weight"), get_post("weight_uom"),  input_num("volume"), get_post("volume_uom"));
            update_record_status($_POST['NewStockID'], $_POST['inactive'],
                'stock_master', 'stock_id');
            update_record_status($_POST['NewStockID'], $_POST['inactive'],
                'item_codes', 'item_code');
            set_focus('stock_id');
            $Ajax->activate('stock_id'); // in case of status change
            display_notification(_("Item has been updated."));
        } 
        else 
        { //it is a NEW part
            add_item($_POST['NewStockID'], $_POST['description'],
                $_POST['long_description'], $_POST['category_id'], $_POST['tax_type_id'],
                $_POST['units'], get_post('fixed_asset') ? 'F' : get_post('mb_flag'), $_POST['sales_account'],
                $_POST['inventory_account'], $_POST['cogs_account'],
                $_POST['adjustment_account'], $_POST['wip_account'], 
                $_POST['dimension_id'], $_POST['dimension2_id'],
                check_value('no_sale'), check_value('editable'), check_value('no_purchase'),
                get_post('depreciation_method'), input_num('depreciation_rate'), input_num('depreciation_factor'), get_post('depreciation_start'),
                get_post('fa_class_id'),  input_num("weight"), get_post("weight_uom"),  input_num("volume"), get_post("volume_uom"));
            display_notification(_("A new item has been added."));
            $_POST['stock_id'] = $_POST['NewStockID'] = 
            $_POST['description'] = $_POST['long_description'] = '';
            $_POST['no_sale'] = $_POST['editable'] = $_POST['no_purchase'] =0;
            set_focus('NewStockID');
        }
        $Ajax->activate('_page_body');
    }
}
if (get_post('clone')) {
    unset($_POST['stock_id']);
    $stock_id = '';
    unset($_POST['inactive']);
    set_focus('NewStockID');
    $Ajax->activate('_page_body');
}
//------------------------------------------------------------------------------------
function check_usage($stock_id, $dispmsg=true)
{
    $msg = item_in_foreign_codes($stock_id);
    if ($msg != '')    {
        if($dispmsg) display_error($msg);
        return false;
    }
    return true;
}
//------------------------------------------------------------------------------------
if (isset($_POST['delete']) && strlen($_POST['delete']) > 1) 
{
    if (check_usage($_POST['NewStockID'])) {
        $stock_id = $_POST['NewStockID'];
        delete_item($stock_id);
        $filename = company_path().'/images/'.item_img_name($stock_id).".jpg";
        if (file_exists($filename))
            unlink($filename);
        display_notification(_("Selected item has been deleted."));
        $_POST['stock_id'] = '';
        clear_data();
        set_focus('stock_id');
        $new_item = true;
        $Ajax->activate('_page_body');
    }
}
function item_settings(&$stock_id, $new_item) 
{
    global $SysPrefs, $path_to_root, $page_nested, $depreciation_methods;
    start_outer_table(TABLESTYLE2);
    table_section(1);
    table_section_title(_("General Settings"));
    //------------------------------------------------------------------------------------
    if ($new_item) 
    {
        $tmpCodeID=null;
        $post_label = null;
        if (!empty($SysPrefs->prefs['barcodes_on_stock']))
        {
            $post_label = '<button class="ajaxsubmit" type="submit" aspect=\'default\'  name="generateBarcode"  id="generateBarcode" value="Generate Barcode EAN8"> '._("Generate EAN-8 Barcode").' </button>';
            if (isset($_POST['generateBarcode']))
            {
                $tmpCodeID=generateBarcode();
                $_POST['NewStockID'] = $tmpCodeID;
            }
        }    
        text_row(_("Item Code:"), 'NewStockID', $tmpCodeID, 21, 20, null, "", $post_label);
        $_POST['inactive'] = 0;
    } 
    else 
    { // Must be modifying an existing item
        if (get_post('NewStockID') != get_post('stock_id') || get_post('addupdate')) { // first item display
            $_POST['NewStockID'] = $_POST['stock_id'];
            $myrow = get_item($_POST['NewStockID']);
            $_POST['long_description'] = $myrow["long_description"];
            $_POST['description'] = $myrow["description"];
            $_POST['category_id']  = $myrow["category_id"];
            $_POST['tax_type_id']  = $myrow["tax_type_id"];
            $_POST['units']  = $myrow["units"];
            $_POST['mb_flag']  = $myrow["mb_flag"];
            $_POST['depreciation_method'] = $myrow['depreciation_method'];
            $_POST['depreciation_rate'] = number_format2($myrow['depreciation_rate'], 1);
            $_POST['depreciation_factor'] = number_format2($myrow['depreciation_factor'], 1);
            $_POST['depreciation_start'] = sql2date($myrow['depreciation_start']);
            $_POST['depreciation_date'] = sql2date($myrow['depreciation_date']);
            $_POST['fa_class_id'] = $myrow['fa_class_id'];
            $_POST['material_cost'] = $myrow['material_cost'];
            $_POST['purchase_cost'] = $myrow['purchase_cost'];
            
            $_POST['sales_account'] =  $myrow['sales_account'];
            $_POST['inventory_account'] = $myrow['inventory_account'];
            $_POST['cogs_account'] = $myrow['cogs_account'];
            $_POST['adjustment_account']    = $myrow['adjustment_account'];
            $_POST['wip_account']    = $myrow['wip_account'];
            $_POST['dimension_id']    = $myrow['dimension_id'];
            $_POST['dimension2_id']    = $myrow['dimension2_id'];
            $_POST['no_sale']    = $myrow['no_sale'];
            $_POST['no_purchase']    = $myrow['no_purchase'];
            $_POST['del_image'] = 0;
            $_POST['inactive'] = $myrow["inactive"];
            $_POST['editable'] = $myrow["editable"];
            $_POST['weight'] = $myrow["weight"];
            $_POST['weight_uom'] = $myrow["weight_uom"];
            $_POST['volume'] = $myrow["volume"];
            $_POST['volume_uom'] = $myrow["volume_uom"];
        }
        label_row(_("Item Code:"),$_POST['NewStockID']);
        hidden('NewStockID', $_POST['NewStockID']);
        set_focus('description');
    }
    $fixed_asset = get_post('fixed_asset');
    text_row(_("Name:"), 'description', null, 52, 200);
    textarea_row(_('Description:'), 'long_description', null, 42, 3);
    stock_categories_list_row(_("Category:"), 'category_id', null, false, $new_item, $fixed_asset);
    if ($new_item && (list_updated('category_id') || !isset($_POST['units']))) {
        $category_record = get_item_category($_POST['category_id']);
        $_POST['tax_type_id'] = $category_record["dflt_tax_type"];
        $_POST['units'] = $category_record["dflt_units"];
        $_POST['mb_flag'] = $category_record["dflt_mb_flag"];
        $_POST['inventory_account'] = $category_record["dflt_inventory_act"];
        $_POST['cogs_account'] = $category_record["dflt_cogs_act"];
        $_POST['sales_account'] = $category_record["dflt_sales_act"];
        $_POST['adjustment_account'] = $category_record["dflt_adjustment_act"];
        $_POST['wip_account'] = $category_record["dflt_wip_act"];
        $_POST['dimension_id'] = $category_record["dflt_dim1"];
        $_POST['dimension2_id'] = $category_record["dflt_dim2"];
        $_POST['no_sale'] = $category_record["dflt_no_sale"];
        $_POST['no_purchase'] = $category_record["dflt_no_purchase"];
        $_POST['editable'] = 0;
    }
    $fresh_item = !isset($_POST['NewStockID']) || $new_item 
        || check_usage($_POST['stock_id'],false);
    // show inactive item tax type in selector only if already set.
  item_tax_types_list_row(_("Item Tax Type:"), 'tax_type_id', null, !$new_item && item_type_inactive(get_post('tax_type_id')));
    if (!get_post('fixed_asset'))
        stock_item_types_list_row(_("Item Type:"), 'mb_flag', null, $fresh_item);
    stock_units_list_row(_('Units of Measure:'), 'units', null, TRUE);
    check_row(_("Editable description:"), 'editable');
    if (get_post('fixed_asset'))
        hidden('no_sale', 0);
    else
        check_row(_("Exclude from sales:"), 'no_sale');
    check_row(_("Exclude from purchases:"), 'no_purchase');
        $result = get_all_item_units();
        while ($unit = db_fetch($result))
            $units[$unit['abbr']] = $unit['name'];
        amount_row(_("Weight:"), "weight", null, null, array_selector("weight_uom", null, $units, array('disabled' => false)));
        amount_row(_("Volume:"), "volume", null, null, array_selector("volume_uom", null, $units, array('disabled' => false)));
        ...