PHP 4.3.3 & IIS (WinXP)

I'm working on a PHP script that queries a MS SQL server. It was originally
developed under Linux and works under Linux without any problems. I'm now
planning on developing it further but it's not even working under WinXP.
Here's part of my code that's causing the problem:

echo "1";
if (!$link = @mssql_connect($db_host, $db_user, $db_pass))
{
echo "2";
$result = 0;
print("<FONT COLOR='Red'><BR><BR><HR><CENTER><B>Error connecting to
$db_host!<HR></B><BR>\n");
}
else
{
echo "3";
mssql_select_db($db_name);
}

It seems to die on: if (!$link = @mssql_connect($db_host, $db_user,
$db_pass)) since only 1 is echo'd (2 & 3 aren't). The problem is no error
message is being returned.

Anyone happen to know why there's isn't an error being returned?