How to check against stock level variable when updating quantities in cart view
I am incorporating stock control into an eCart site and it's working fine when adding an item but I need to insert some checking code when the cart is updated if the quantity is changed. I need a steer as to where I should put any code. I could add a column to the cart items to hold the stock level so I can then compare that to the quantity in the cart, or I could do a query to check it, but I don't know where any of that code should go.
Can you point me in the right direction?