error on payment module

[coder1ab]

I am setting up a duplicate cart on 1 domain name using a separate database. DB is done and all files are copied. I think all paths have been adjusted to the newly named directory for the cart. This cart uses authorizenet payment module which is working fine on the original cart. On the new cart, when I go to Payment Modules in the admin panel I receive the following message:

 

Fatal error: Cannot redeclare class authorizenet in /web/collegiate/includes/modules/payment/authorizenet2.php on line 13

 

PLEASE help me. I am definitely not the pro with php.

 

Thanks!