Copying a website to a new domain

Hi.

iv made a website using drupal, but i want to copy this website to a new domain.

i first copied the drupal 7, set it up and added the database, but didnt have the modules etc..

so when i copied all the information and replaced it.

it keeps giving the error:

PDOException: SQLSTATE[28000] [1045] Access denied for user 'sga931'@'localhost' (using password: YES) in lock_may_be_available() (line 167 of /home/sites/al-mamun.co.uk/public_html/connect/includes/lock.inc).

any ideas!!! i have had this problem for long time, have no idea.

when i go to line 167 it says:

$lock = db_query('SELECT expire, value FROM {semaphore} WHERE name = :name', array(':name' => $name))->fetchAssoc();

thanks. also where it says Access denied for user 'sga931'@'localhost', thats from my old website.. shouldnt be saying this.