Foren / Cotonti / Support / mysql error ?

I get this warning in the error log

PHP Warning: mysql_close(): supplied argument is not a valid MySQL-Link resource in /home/blah/public_html/system/database.mysql.php on line 25

And below is the part of the code the above is referring to.

if (!defined('SED_CODE')) { die('Wrong URL.'); }

function sed_sql_affectedrows()
{ return (mysql_affected_rows()); }

/* ------------------ */

function sed_sql_close($id='')
{ return(mysql_close($id)); }

/* ------------------ */

function sed_sql_connect($host, $user, $pass, $db)
{
$connection = @mysql_connect($host, $user, $pass) or sed_diefatal('Could not connect to database !<br />Please check your settings in the file datas/config.php<br />'.'MySQL error : '.sed_sql_error());
$select = @mysql_select_db($dbName, $db, $connection) or sed_diefatal('Could not select the database !<br />Please check your settings in the file datas/config.php<br />'.'MySQL error : '.sed_sql_error());
return($connection);
}

Thanks in advance ...Stig