problems with phpbb forum

Can't open file: 'php_sessions.MYI' (errno: 145)  :- getting that error in my forum, I asked in another forum and they said it can be tables corrupted, how can I fix it? thanks

I guess you are using phpbb forum and the session table is corrupted. You can get that fixed by repairing the tables through PHPMyAdmin or you can ask your host to repair the database through mysql command line.