How to Show Product id and manufacturer name Virtuemart Featured Products module

[nalabianmv]

Hi  ,
I am using joomla 1.5 and virtuemart 1.1.9, and also i am new to joomla.I am developing a website for online book sales
I want to show product id and manufacturer name ,book isbn no in featured poducts  module,and i tried the following code to show the manufacturer name,but still with no luck,
In mod_virtueamrt_featuredprod.php

$ps_product->show_snapshot($db->f("product_sku"), $show_price, $show_addtocart);?>

  after this line  i added the  following code to show manufacturer name
echo "<div> Manufacturer Name: "$db->f("mf_name") ."</div>";

but this is not working for me...Anyone got any ideas???

thanks in advance
vmani