bypassing create account success with empty cart

[craftzombie]

I was wondering if this is possible and if it isn't a time consuming pain, can someone please guide me...

I changed my filenames.php file to bypass the create account success page and go directly to checkout_shipping. But if the person has an empty cart and is just signing up for an account, they get a "Login Time Out ---
Whoops! Sorry, but you are not allowed to perform the action requested. "

Is there some kind of "if" statement I can add to the create account.php that directs the customer to checkout_shipping if there are items in the cart and to maybe the home page or something if their cart is empty? (I could easily put a little note near the submit button on the create account page that lets them know which places they will be directed to depending on their circumstances)

Any help would be greatly appreciated

(or even better... could we change back the filename.php file back to normal and have the new "if" statement I mentioned above have the create account success page appear only if there are no items in the cart, and then have it not appear and just go to checkout_shipping if there are items in the cart?)

P.S. I hope I'm not confusing you!!