[RESOLVED] can't connect to MSSQL

I'm using:
Microsoft SQL Server 2005 Express
PHP Version 5.2.3 (ISAPI)
Windows 2K
IIS

I can't change any of these, set by way up high.

I get an "Unable to connect to server" message.

I have updated ntwdlib.dll to version 8.00.194 in winnt/system32 and /php
I have set mssql.secure_connection = off in php.ini

$conn=mssql_connect("localhost,1433", "sa", "mypassword");
if (! $conn) Die("Error opening database: ".mssql_get_last_message());

Also tried "localhost" and "servername" "servername\SQLEXPRESS" and
"servername,1433" and "servername\SQLEXPRESS,1433"

I can connect to the database using the same credentials when I use Microsoft SQL Server Management Studio Express, but no luck from within php.

Any ideas what could be wrong?
Can I get a more detailed error than "Unable to connect to server" ?

Not much hair left...

I don't know why, but "servername\SQLEXPRESS" worked whereas "servername\SQLEXPRESS" didn't.

This works:

$conn=mssql_connect("servername\\SQLEXPRESS", "sa", "mypassword");
if (! $conn) Die("Error opening database: ".mssql_get_last_message());

Happy now!

I don't know why

Backslashes in double quote delimited strings must be escaped, with a backslash. Read the PHP manual on strings for more information.