500 internal server error

My client requested a change to copyright footer on website - http://www.one3ip.com and after making the change, I am locked out of the wp-admin, plus cannot access any menu pages.

I had previously contacted Copyblogger Media Support with the following message:

I need to modify the copyright notice in the footer to read, “© 2011 – [current year] ONE3 IP MANAGEMENT – ALL RIGHTS RESERVED”. I’ve figured everything out except for getting the static “2011” in there. I found the “Simple Edits” page in WordPress, but it looks like the year numbers are handled by “[footer_copyright],” so I need to know how to access/edit that function/variable.

I received the following reply:

You can add something like this to your functions.php file:

//* Customize footer
remove_action( 'genesis_footer', 'genesis_do_footer' );
add_action( 'genesis_footer', 'custom_footer' );
function custom_footer() {
?>
<p>© Copyright 2011 - <?php echo date('Y'); ?> Your Website Name</p>
<?php
}

Not really knowing code, but having a good idea - I copied the info to the functions.php file and received the 500-internal server error message. I deleted the changes, but still having problems. Hoping someone can respond and provide some information. Thanks. ....Paul