risolvere questa join ??

[searedone]

Ciao a tutti,
sto provando a fare questa join ma mi da' il seguente errore :


You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'messages INNER JOIN users U ON (U.uid='54' ) WHERE M.uid_fk=U.uid OR' at line 3

La join è questa

class Wall_Updates { 


     
     // Updates        
      public function Updates($uid)  
    { 
     
     
         $query = mysql_query( "SELECT M.msg_id, M.uid_fk, M.message, M.created, U.username FROM 
        messages  INNER JOIN messages M  ON (M.uid_fk='$uid' ) 
        messages INNER JOIN users U ON (U.uid='$uid' ) 
         
WHERE    
M.uid_fk=U.uid OR M.uid_fk='$uid' OR M.uid_fk IN (SELECT user_1 FROM relationship AS r WHERE r.user_2 = '$uid' AND r.amico = 'S') OR M.uid_fk IN (SELECT user_2 FROM relationship AS r WHERE r.user_1 = '$uid' AND r.amico = 'S') order by M.msg_id desc  ") or die(mysql_error());      
         while($row=mysql_fetch_array($query)) 
        $data[]=$row; 
        return $data; 
         
         
        
         
         
         
    } 

Le tabelle sono

messages
relationship
users

per quale motivo deve essere sempre così incasinata una join