The 3.1 version of WordPress adds an administrator bar directly on the front end of your site. Although it can be disabled for each account, this tip will teach you how to delete it directly from functions.php.
Go to the menu, then Appearance and then to Editor. In the right sided list, click the functions.php file.
However, we advise you to backup through an FTP client to easily make a copy of the file. You might get a blank page after saving as a result of the placement error code snippet:
---
function my_function_admin_bar () {
return false;
}
add_filter (˜show_admin_bar™, ˜my_function_admin_bar™);
Update: Many thanks to David of digitalraindrops for correcting the snippet.
So, just add these lines to the file – typically after a PHP function.
Otherwise, do not forget to frame tags <?php and ?> .
Remember to Update the file.
Go back to your site and verify that the administrator bar has disappeared. Also try a different user account to see the actual change.
The admin bar introduced since version 3.1 of WordPress may yet prove useful to the novice user but useless in some cases specific use of the platform.

Hi Abhishek,
Have the function the wrong way around, the word function should come before the function name fatal error:
Switch it round and it works fine:
function my_function_admin_bar () {
return false;
}
add_filter (‘show_admin_bar’, ‘my_function_admin_bar’);
David
Thank you very much David for the correction.
Its corrected now!