can I add another host name refer to the same commerce site?

My case is
i have a running commerce 2007 site , what i have done that i create
another web site rfering to the same path,
but it gives errors in basket bibiline when i switched from site to
site , also in the ADS like "ProgID: Commerce.CSFLoadHistory.1
HttpContext.Current is null
"
my Q now how to enforce to clear the cash when i switch from site to
site
my 2nd Q is how also make the users loggen in 1 site logged out in the
othert site

Deep Regards