Help needed... FORMS & PHP (not as noob as you think)

[Deaths]

Could you maybe give an example?
What I'm doing is this:

PHP Code:

globalize($_POST, array('products[1][quantity]'));
        foreach ($products AS $orderid=>$quantity)
        {
              foreach ($quantity AS $key=>$value)
                  {
                      echo "$products";
                  }
        } 


It then errors me out:

Warning: Invalid argument supplied for foreach() in /products.php on line 70

This is on line 70:

PHP Code:

foreach ($products AS $orderid=>$quantity)