Forum Can't delete forum

[محروم.كوم]

Hello !
I am trying to delete a forum.
but i am getting below error in Admin CP:

Code:
Database error in vBulletin 4.0.2:

Invalid SQL:

DELETE searchcore, searchcore_text
FROM vbtesttable_searchcore AS searchcore JOIN

vbtesttable_searchcore_text AS searchcore_text ON
searchcore.searchcoreid = searchcore_text.searchcoreid
WHERE searchcore.groupcontenttypeid = 2 AND
searchcore.groupid = 87857;

MySQL Error : Table './***********/vbtesttable_searchcore_text' is marked as crashed and should be repaired
Error Number : 145
Request Date : Friday, May 14th 2010 @ 03:19:31 AM
Error Date : Friday, May 14th 2010 @ 03:19:32 AM
Script : http://******/home/admincp/forum.php?do=kill
Referrer : http://******/home/admincp/forum.php?do=remove&f=182&s=
IP Address : 109.123.86.176
Username : ******
Classname : vB_Database_MySQLi
MySQL Version : 5.0.90-community
And when i try to delete all posts in that forum one by one, i am getting below error:

HTML Code:
Database error in vBulletin 4.0.2:

Invalid SQL:

DELETE searchcore, searchcore_text
FROM vbtesttable_searchcore AS searchcore JOIN
vbtesttable_searchcore_text AS searchcore_text ON
searchcore.searchcoreid = searchcore_text.searchcoreid
WHERE searchcore.groupcontenttypeid = 2 AND
searchcore.groupid = 51893;

MySQL Error : Table './******/vbtesttable_searchcore_text' is marked as crashed and should be repaired
Error Number : 145
Request Date : Friday, May 14th 2010 @ 0346 AM
Error Date : Friday, May 14th 2010 @ 0346 AM
Script : http://*******/home/inlinemod.php?do...,113262,112322
Referrer : http://*******/home/inlinemod.php?forumid=182
IP Address : 109.123.86.176
Username : ***********
Classname : vB_Database_MySQLi
MySQL Version : 5.0.90-community __DEFINE_LIKE_SHARE__