初学，不知是何错误,该如何解决？

[9981]

<?php
$conn = @mysql_connect("localhost","user","userpw")
or die("Can't connect to database server!");
mysql_select_db("dbname")
or die("Can't select database!");
$qurey = "SELECT product_name,product_type FROM product";
$result = mysql_query($query);
if (mysql_num_rows($result) == 0) {
echo "ok";
}
else {
echo "on";
}
?>

出现错误：
Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /data/www/test.php on line 8
ok

不知该如何解决？