Error message

• Warning: Cannot modify header information - headers already sent by (output started at /apps/vhosts/euoag/www/includes/common.inc:2820) in drupal_send_headers() (line 1501 of /apps/vhosts/euoag/www/includes/bootstrap.inc).
• Error: Call to undefined function euoag_delete_files() in eval() (line 1 of /apps/vhosts/euoag/www/sites/all/modules/elysia_cron/elysia_cron.module(1480) : eval()'d code).