Migrating wordpress…

Warning: Cannot modify header information – headers already sent by (output started at /home/content/t/i/m/timsimons/html/blog/wp-content/themes/default/functions.php:1188) in /home/content/t/i/m/timsimons/html/blog/wp-login.php on line 9

I have a site hosted on godaddy. They offer to install wordpress but the system creates the wordpress files in a directory domainname.com/wordpress. I want the wordpress files to be located in blog.domainname.com.

In the admin functions I changed the location of the files to blog.domainname.com then moved all the files to that directory.

I’m getting the error above when I login.

Help me! What can I do so wordpress works with my sub-domain.