showing error messages such as below. Can anyone suggest how to fix this?

Rob

Warning: Can't open file: 'cache.MYI' (errno: 145) query: SELECT data, created, headers, expire FROM cache WHERE cid = 'variables' in /home/robmania/public_html/realestatezoo/includes/database.mysql.inc on line 120

Warning: Can't open file: 'cache.MYI' (errno: 145) query: LOCK TABLES cache WRITE in /home/robmania/public_html/realestatezoo/includes/database.mysql.inc on line 120