CREATE TABLE IF NOT EXISTS `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `login` text NOT NULL,
  `haslo` text NOT NULL,
  `email` text NOT NULL,
  `zarejestrowany` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  `rola` tinyint(4) NOT NULL DEFAULT '1',
  `czas` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT 'Czas aktualny',
  `czas_last` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  `zalogowany` tinyint(4) NOT NULL DEFAULT '0',
  PRIMARY KEY (`id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=30;

<?php
// ------------------------
mysql_query("UPDATE user SET czas=Now()");
// ------------------------

$getLogged = mysql_query("Select login,czas From user Where czas + Now()") or die(mysql_error());
if(mysql_num_rows($getLogged) > 0){
while($logged= mysql_fetch_array($getLogged)){
echo $logged['login']; ?> <br />
<?php
}
}
else echo "<center><font color='red' size='2'>Brak użytkowników online!</font></center>";
?>