syntax error in mysql

[snobird1211]

im getting this error on my site now for on reason. everything was working fine and then today peolpe who play aracde and get high scores are getting this

mySQL query error: SELECT * FROM games_session WHERE sessid= LIMIT 1

mySQL error: 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 'LIMIT 1' at line 1
mySQL error code:
Date: Thursday 15th of March 2007 05:35:22 AM

thanks in advance