Error message

• Warning: Cannot modify header information - headers already sent by (output started at /home/umspti/public_html/includes/bootstrap.inc:3573) in drupal_send_headers() (line 1236 of /home/umspti/public_html/includes/bootstrap.inc).
• Warning: Cannot modify header information - headers already sent by (output started at /home/umspti/public_html/includes/bootstrap.inc:3573) in drupal_send_headers() (line 1236 of /home/umspti/public_html/includes/bootstrap.inc).
• Warning: Cannot modify header information - headers already sent by (output started at /home/umspti/public_html/includes/bootstrap.inc:3573) in drupal_send_headers() (line 1236 of /home/umspti/public_html/includes/bootstrap.inc).
• Warning: Cannot modify header information - headers already sent by (output started at /home/umspti/public_html/includes/bootstrap.inc:3573) in drupal_send_headers() (line 1236 of /home/umspti/public_html/includes/bootstrap.inc).
• Warning: Cannot modify header information - headers already sent by (output started at /home/umspti/public_html/includes/bootstrap.inc:3573) in drupal_send_headers() (line 1236 of /home/umspti/public_html/includes/bootstrap.inc).