can’t log in to admin

Can anyone help me? for some reason I can’t log in to my admin area, this is the message I recieve when I enter this bloggapleeze.com/wp-admin into the address bar.
Warning: Cannot modify header information – headers already sent by (output started at /home/blogpor8/public_html/wp-content/themes/8-peoplearetalkin/functions.php:419) in /home/blogpor8/public_html/wp-includes/pluggable.php on line 689