Hello. First off I am not sure if this is the best or even a possible way of approaching this but I will try to explain what I need to pull off. I have a shopping cart that I am trying to add some custom buttons to that will update the quantity of the items in the cart. I am using oscommerce and would like to use the form they currently have in place for this functionality so my idea was to insert an image like so:

<img src="includes/languages/english/images/buttons/update_cart.png" border="0" alt="Update Quantity" style="cursor:pointer;" onclick"document.cart_quantity.cart_quantity[].value = 2;document.cart_quantity.submit();">

So, ultimately I need this button to update the value in the quantity field then submit the form so the cart will update with a value I choose (was 2 in example above). If anybody has any idea how I can do this I would really appreciate it!

Well first get the value of the quantity field. Then add 1 to that onclick.