I need to connect remotely to MS SQL Server 2000 using

php.I am using the following codes:

$dbhost = "IP address of server";
$dbuser = "username";
$dbpass = "password";
mssql_connect($dbhost, $dbuser, $dbpass) or die("Unable to

connect to $db";

But I keep getting the following error:
PHP Warning: mssql_connect() [function.mssql-connect]:

message: Login failed for user '(null)'. Reason: Not

associated with a trusted SQL Server connection. (severity

14).

I have already set mixed mode authentication on the

server, but it did not help.

Please help