If your using: http://code.google.com/p/php-twitter/ which is what it looks like... then you need to specify $twit->username = ""; $twit->password = ""; $twit->User-Agent = ""; then call the $twit->update
If that's not the correctly library, you still should have to set those somehow, either statically in the class.twitter.php file or through your script, like above.
