Shipping for Certain Products

Hi, does anyone know a way to activate a shipping module just for a certain product. My client typically uses USPS to ship their products however they have entered in an agreement with UPS to ship one of their products. Is their a way in Zen Cart to display only that shipping module if a person has that certain product in their shopping cart?

Thanks. I appreciate any help.

What is your shipping rule if a customer has a cart with several products that require BOTH UPS and USPS ?

If the user orders multiple products and one of them is for UPS then all the products would go out via UPS. That would probably be a lot easier than saying this product is shipped via this and that product is shipped via the other one.

There is a function in the shopping_cart.php class where you can test the contents of the shopping cart to see what is in there in relation to the products table:

/**

• Method to calculate the number of items in a cart based on an abitrary property
• $check_what is the fieldname example: 'products_is_free'
• $check_value is the value being tested for - default is 1
• Syntax: $_SESSION['cart']->in_cart_check('product_is_free','1');
• @param string product field to check
• @param mixed value to check for
• @return integer number of items matching restraint
  */
  function in_cart_check($check_what, $check_value='1') {