Email Not working and neither is newsletter

[LianeLeedom]

Anyone know what this means:

 

1064 - 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 '-20, 20' at line 1

 

select newsletters_id, title, length(content) as content_length, module, date_added, date_sent, status, locked from newsletters order by date_added desc limit -20, 20

 

Thanks

LJL