$query = sqlsrv_query("select * from sessions where password='$password' AND username='$username'");
$rows = sqlsrv_num_rows($query);
if ($rows == 1) {
    $_SESSION['login_user']=$username;
    header("location: profile.php");
} else {
    $error = "Username or Password is invalid";
}

$serverName = "serverNameinstancename";
$connectionInfo =
    array( "Database"=>"dbName", "UID"=>"username", "PWD"=>"password" );
$conn = sqlsrv_connect( $serverName, $connectionInfo);

$params = array($username, $password);
$stmt = sqlsrv_query
            ($conn,
            'select * from sessions where password=? AND  username=?',
            $params);