Historic Coins

1) Fix error message when clicking checkout with an empty cart 2) Prevent orders of quantities more than in stock (either a validation check once a product has been added to cart against the physical stock level - and if the quantity is higher than the stock then return a page saying "You cannot order more than the X available in stock". OR - if its easier, restrict the drop down box for quantities on the product details page (template is at [login to view URL]) to have a maximum value equal to the stock leve - whichever you prefer!