// First starts a session
	session_start();

	// Function that registers a user
	// This function should be called when a login is performed.
	// Returns true if the user was logged in, false otherwise.
	function registerUser($username,$password) {
		require "config.php";
		// Connect to the database and checks if the user / password
		// combinaison matches any existing database entry
		$mysql_link = mysql_connect($db_hostname,$db_username,$db_password) or die("Failed to connect to MySQL");
		mysql_select_db($db_database, $mysql_link) or die ("Unable to select database!");
		$query = "SELECT ".$db_fld_users_id." FROM ".$db_tbl_users." WHERE ".$db_fld_users_username." LIKE '".$username."' AND ".$db_fld_users_password." LIKE '".encrypt($password,$enckey)."'";
		// $r_query = mysql_query($query, $mysql_link);// or mysql_error() and die("Failed to execute_query");
		$r_query = mysql_query($query, $mysql_link) or die("Failed to execute_query");
		if (mysql_num_rows($r_query) != 0) {
			$query_row = mysql_fetch_array($r_query);
			writeSessionUserIds($query_row[$db_fld_users_id], $username);
			// Writing connection date into database
			writeUserLoginDate($query_row[$db_fld_users_id]);
			// Increasing number of connections for this user
			writeUserConnection($query_row[$db_fld_users_id]);
			return true;
			exit;
		} else {
			return false;
			exit;
		}
	}