Clearing UPS Shipping Calculation when leaving checkout pages
I am trying to clear the shipping calculation after a customer decides to go back to my website to add or remove products from the shopping cart. I do not think it is the best user experience for my customers see the previously calculated UPS shipping charge in the shopping cart.
Is it possible to set a session variable or cookie that would ONLY remove the shipping data if a customer decides to go back and adjust his order? As of right now, the only way a customer can clear the shipping data of the previous UPS calculation is to click the "clear cart" button.
Any suggestions on how to do this will be greatly appreciated.