Error message

• Warning: Cannot modify header information - headers already sent by (output started at /home/losyapas/public_html/includes/common.inc:2777) in drupal_send_headers() (line 1516 of /home/losyapas/public_html/includes/bootstrap.inc).
• Error: Call to a member function execute() on null in eval() (line 7 of /home/losyapas/public_html/modules/php/php.module(80) : eval()'d code).