function random_student()
{
$email = "test_" . rand();
$uid = BoincUser::insert("(email_addr) values ('{$email}')");
if (!$uid) {
echo "can't add user";
exit;
}
$sex = rand(1, 2);
$birth_year = rand(1938, 1998);
BoltUser::insert("(user_id, sex, birth_year) values ({$uid}, {$sex}, {$birth_year})");
return $uid;
}