A little problem

[mihu]

Hi there boys!

I think i have a little conversion problem to my application;
i am tring to retrive the number of rows in mysql to make the login script and .. it tels me this error;

if(isset($_POST['activateLoginForm'])) {

     $user = trim($_POST['username']);
     $pass = trim($_POST['passwords']);

     echo $user."\n";
     echo $pass;

     $conn = new sqlServer();
     $conn->setHost("localhost");
     $conn->setUser("root");
     $conn->setPassword("root");
     $conn->openConn();

     $query = "SELECT count(*) from members where username ='$user' AND password='$pass'";
     $result = mysql_query($query);
     $count = mysql_num_rows($result);
     echo $count;
     if ( $count == 0) { die("invalid username and password"); }


   }

And .. when i run the page:

Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in D:\xampp\xampp\htdocs\work\orders\login_check.php on line 20

Does somebody knows what should i do? :(