admin problems :( URGENT!!!!

I cant change any of my appearance through the editor in my admin panel. It says:

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-login.php on line 290

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-login.php on line 302

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 689

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 690

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 691

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 692

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 693

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 694

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 697

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 698

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 699

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 700

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 703

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 704

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 705

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 706

Warning: Cannot modify header information – headers already sent by (output started at /home/tunermag/public_html/wp-content/themes/streamline_10/functions.php:28) in /home/tunermag/public_html/wp-includes/pluggable.php on line 865