If you have not yet logged in when you click the submit order button in your shopping cart, you will be taken to the Log in/Register screen. If you allowed a cookie to be set to remember you when you return to our site, you will not have be prompted to log in at this point. If you have trouble logging in, see the section on My Online Account.
Once you have logged in, you will be taken back to your shopping cart. You can then hit the submit order button and proceed with your order.