Need help with oscommerce error and install contribution

i want some one to fix this error

Fatal error: Cannot redeclare tep_db_connect() (previously declared in /home/domain/public_html/admin/includes/functions/[url removed, login to view]) in /home/adults/public_html/admin/includes/functions/[url removed, login to view] on line 13

and install this properly as i tried and then i get the error ONLY PHP or oscommerse experts thanks

Taidot: PHP, Verkkosivujen suunnittelu

Projektin tunnus: #4941