Error installation [function.mysql-connect] wp-includes

Hi everyone !

So, I am having a problem installing wordpress.

I put the information in the wp_config file this way :

'// ** Réglages MySQL - Votre hébergeur doit vous fournir ces informations. ** //
/** Nom de la base de données de WordPress. */
define('XXXXXX','wordpress');

/** Utilisateur de la base de données MySQL. */
define('XXXXXX','username');

/** Mot de passe de la base de données MySQL. */
define('XXXXX,'password');

/** Adresse de l'hébergement MySQL. */
define('db474772390.db.1and1.com','localhost');

/** Jeu de caractères à utiliser par la base de données lors de la création des tables. */
define('DB_CHARSET','utf8');'

I did not touch the last line.
I put everything in my server and had some errors that I could corrects but this one is still here. When I go on my webpage this appear :

Warning: mysql_connect() [function.mysql-connect]: Unknown MySQL server host ‘1&1.com’ (1) in /homepages/16/d474582610/htdocs/wp-includes/wp-db.php on line 1141

and the code line in the file here :

'if ( WP_DEBUG ) {
			$this->dbh = mysql_connect( $this->dbhost, $this->dbuser, $this->dbpassword, $new_link, $client_flags );
		} else {
			$this->dbh = @mysql_connect( $this->dbhost, $this->dbuser, $this->dbpassword, $new_link, $client_flags );
		}

		if ( !$this->dbh ) {
			wp_load_translations_early();
			$this->bail( sprintf( __( "
<h1>Error establishing a database connection</h1>
<p>This either means that the username and password information in your <code>wp-config.php</code> file is incorrect or we can't contact the database server at <code>%s</code>. This could mean your host's database server is down.</p>
<ul>
	<li>Are you sure you have the correct username and password?</li>
	<li>Are you sure that you have typed the correct hostname?</li>
	<li>Are you sure that the database server is running?</li>
</ul>
<p>If you're unsure what these terms mean you should probably contact your host. If you still need help you can always visit the <a href='http://ww.wp.xz.cn/support/'>WordPress Support Forums</a>.</p>'

So i don’t really understand what I did wrong, because there must be something but I really can’t see what.

If someone could help me I would really appreciate it because I am starting to become crazy !