can't use adminCP

[rhondajean]

I hope someone can help me. My forum is working well but when I tried to log into the admin CP, it loads the side bar but gives me this message instead of the normal:

Database error in vBulletin 4.0.0:

Invalid SQL:
SELECT SUM(filesize) AS size FROM filedata;

MySQL Error : Table './downtoe4_forum/filedata' is marked as crashed and last (automatic?) repair failed
Error Number : 144
Request Date : Saturday, February 2nd 2013 @ 01:31:33 PM
Error Date : Saturday, February 2nd 2013 @ 01:31:34 PM
Script : http://downtoearthforums.com/admincp/index.php?do=home
Referrer : http://downtoearthforums.com/admincp/
IP Address : 121.223.98.116
Username : rhondajean
Classname : vB_Database
MySQL Version : 5.5.29-log