MSSQL connect problemmer

Hej jeg har set mig blind...
denne kode giver bare en advarsel..
men jeg kan ikke se noget galt i den..
PS: har aldirg prøvet at oprette en mssql connect før

<?php
$connection = mssql_connect("localhost\SQLEXPRESS,1433","user","pass");
mssql_select_db("NotaWEB", $connection);
mssql_close();
?>

Warning: mssql_connect() [function.mssql-connect]: Unable to connect to server: localhost\SQLEXPRESS,1433 in D:\wwwroot\www.heliosnorge.no\public_html\admin\inc\config.php on line 3

Warning: mssql_select_db(): supplied argument is not a valid MS SQL-Link resource in D:\wwwroot\www.heliosnorge.no\public_html\admin\inc\config.php on line 4

Warning: mssql_close() [function.mssql-close]: Unable to connect to server: (null) in D:\wwwroot\www.heliosnorge.no\public_html\admin\inc\config.php on line 6

Warning: mssql_close() [function.mssql-close]: A link to the server could not be established in D:\wwwroot\www.heliosnorge.no\public_html\admin\inc\config.php on line 6