can not access to database in moodle

I am using [moodle](http://www.moodle.org) and I change location of my web site, but I am facing this error. My config.php is: <?php /// Moodle Configuration File unset($CFG); $CFG->dbtype = 'mysql'; $CFG->dbhost = 'localhost'; $CFG->dbname = 'lightsys_test'; $CFG->dbuser = 'lightsys_test'; $CFG->dbpass = '123456a'; $CFG->dbpersist = false; $CFG->prefix = 'mdl_'; $CFG->wwwroot = 'http://www.lightsystem.ir/aya/moodle'; $CFG->dirroot = '/home/lightsys/public_html/aya/moodle'; $CFG->dataroot = '/home/lightsys/public_html/aya/moodledata'; $CFG->admin = 'admin'; $CFG->directorypermissions = 00777; // try 02777 on a server in Safe Mode require_once("$CFG->dirroot/lib/setup.php"); // MAKE SURE WHEN YOU EDIT THIS FILE THAT THERE ARE NO SPACES, BLANK LINES, // RETURNS, OR ANYTHING ELSE AFTER THE TWO CHARACTERS ON THE NEXT LINE. // /home/lightsys/public_html/aya/moodle/ ?> And my error is: >Error: Database connection failed. > >It is possible that the database is overloaded or otherwise not running properly. > >The site administrator should also check that the database details have been correctly specified in config.php