horror de codigo

Fatal error: Uncaught exception 'Zend_Db_Adapter_Exception' with message 'The mssql driver is not currently installed' in /home/slovacus/Resources/Library/ZendFramework-1.11.11/library/Zend/Db/Adapter/Pdo/Abstract.php:112 Stack trace: #0 /home/slovacus/Resources/Library/ZendFramework-1.11.11/library/Zend/Db/Adapter/Pdo/Mssql.php(137): Zend_Db_Adapter_Pdo_Abstract->_connect() #1 /home/slovacus/Resources/Library/ZendFramework-1.11.11/library/Zend/Db/Adapter/Abstract.php(459): Zend_Db_Adapter_Pdo_Mssql->_connect() #2 /home/slovacus/Resources/Library/ZendFramework-1.11.11/library/Zend/Db/Adapter/Pdo/Abstract.php(238): Zend_Db_Adapter_Abstract->query('SELECT 8323 -- ...', Array) #3 /home/slovacus/Resources/Library/ZendFramework-1.11.11/library/Zend/Db/Adapter/Abstract.php(827): Zend_Db_Adapter_Pdo_Abstract->query('SELECT 8323 -- ...', Array) #4 /home/slovacus/Projects/PHP/Zend/clasificados2/src/library/Ec/Site/Abstract.php(92): Zend_Db_Adapter_Abstract->fetchOne('SELECT 8323 -- ...') #5 /home/slovacus/Projects/PHP/Zend/clasifi in /home/slovacus/Resources/Library/ZendFramework-1.11.11/library/Zend/Controller/Plugin/Broker.php on line 336