admin interface doesn´t work?????

I´had install the guestbook.
But only the Admin login doesn´t work.
USER and PW are correct. But when i click the login button nothing happens????

What may be the problem?

Do you receive any warnings after trying to login? What is the URL of your guestbook? Also if possible, please email the PHP Info output of your site to webmaster@digioz.com .

To get a PHP Info, create a file called "phpinfo.php", and inside it write:

Navigate to that page and save and email the resulting output to the browser to the email above.

Thanks,
Pete