Скиталец, в head
$totalonsite = $datauser['total_on_site'];
if ($datauser['lastdate'] > (time() - 300)) {
$totalonsite = $totalonsite + time() - $datauser['lastdate'];
}
mysql_query("UPDATE `users` SET $sql
`movings` = '$movings',
`total_on_site` = '$totalonsite',
`lastdate` = '" . time() . "'
WHERE `id` = '$user_id'
");