help w/sql query restructuring

i need help modifying a mysql select statement to get the CORRECT username. the way i have it now it goes by the uid in the forum, i want the uid on the post table.
below is a print out of the cli when running the first construction, finding out which it was using, and then what happened when i tried to fix it.

Quote: mysql> select users.username,threads.locked,threads.fid,threads.tid,fal from posts left join threads using (tid) left join forums using (fid) natural join users where pid=24;
+----------+--------+-----+-----+-----+
| username | locked | fid | tid | fal |
+----------+--------+-----+-----+-----+
| Neo | 1 | 2 | 16 | 0 |
+----------+--------+-----+-----+-----+
1 row in set (0.16 sec)

mysql> select uid from threads where tid=16;
+-----+
| uid |
+-----+
| 28 |
+-----+
1 row in set (0.00 sec)

mysql> select uid from forums where fid=2;
+-----+
| uid |
+-----+
| 1 |
+-----+
1 row in set (0.00 sec)

mysql> select uid from posts where pid=24;
+-----+
| uid |
+-----+
| 28 |
+-----+
1 row in set (0.00 sec)

mysql> select users.username,threads.locked,threads.fid,threads.tid,fal from posts natural join users left join threads using (tid) left join forums using (fid) where pid=24;
ERROR 1054: Unknown column 'users.tid' in 'on clause'
mysql> select users.username,threads.locked,threads.fid,threads.tid,fal from posts left join users using (uid) left join threads using (tid) left join forums using (fid) where pid=24;
ERROR 1054: Unknown column 'users.tid' in 'on clause'