[PHP] php- something that i don't understand

[Yassel Omar Izquierdo Souchay]

Hey guys 
here is my code

4: mysql_connect() or die ("Problemas conectandose a la base de datos"); 
5: $query="select * from info where FirstName='$FirstName' and 
6: LastName='$LastName' and email='$email'"; 
7: $result = mysql_db_query("users", $query); 
*8: $r=mysql_fetch_array($result); ************
9: $count=$r["count"];

and i follow redcieving this message

Warning: Supplied argument is not a valid MySQL result resource in 
c:\inetpub\wwwroot\PhpAndMysqlTest\test2\reg1.php3 on line 8


thanks for your answers
Yassel