use the code from here http://themes.svn.wordpress.org/blackbird/1.1.5/footer.php to replace what you have deleted.
or download a new copy of the theme http://wordpress.org/extend/themes/download/blackbird.1.1.4.zip , unzip it on your computer, and upload footer.php to your server (using ftp).
Thanks a lot Alchymyth.
I was able to restore the footer with your help.
Thanks again