Using the back button to change the number of items required, after the commit to buy button has been clicked, generates a new additional order and does not simply amend the quantity being ordered. Why is the back button available when in fact it obviously continues from that point? Where this occurs, the buyer then has to contact the seller direct to have the unwanted purchase order cancelled. It is a simple fix - do not allow the back button where clicking it does not in fact take you back one or more steps.
