Help with a foreach statement

I am writing a shopping cart. Products assigned in the following fashion: $_SESSION['selection'][$product]=$quantity; I am wanting to display the list of products in the shopping cart in a list for the user to see as they continue shopping. I put the SESSION variable into $cart $cart = $_SESSION['selection']; then I start the foreach and this is where I get messed up. I am trying to ECHO the following syntax to the screen with each selected product: The part I need help with is to write the foreach loop to give me $product (so I may query the database to find out the product name) and the $quantity (so I may show the user what they are purchasing). The part that is messing me up is that this is an array. My ECHO statement should look like this: echo "<li><a href=\"" . $path_to_shopping_cart . "product/" . $cart[$product_id] . "/\">" . $product_name . "</a> - " . $quantity . "</li>\r\n";