problemer med mysql_num_rows

$klanid = $claninfo[id];
$playersinclan = mySQL_Num_Rows(mySQL_Query("SELECT * FROM players where player_clan = '$klanid' and player_game = '1' and player_accepted '1'"));
if($playersinclan >= 5) {
    echo "der er 5";
    exit;
}else{
    echo "der er ikke 5";
    exit;
}

CREATE TABLE `players` (
  `id` int(11) NOT NULL auto_increment,
  `player_user` varchar(32) NOT NULL default '',
  `player_clan` varchar(32) NOT NULL default '',
  `player_game` varchar(32) NOT NULL default '',
  `player_accepted` char(1) NOT NULL default '',
  PRIMARY KEY  (`id`)
) TYPE=MyISAM AUTO_INCREMENT=960 ;

Fælterne er i databasen men den reagere sku ikke på det

kan umidelbart ikke lure hvorfor jeg får denne fejl

Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /web/onedaycup/onedaycup.com/dev/login.php on line 34