Mysql passwords

php login_check.php = array_key_exists() expects parameter 2 to be array, boolean given in /var/www/ross.net/web/login_check.php on line 21

string(19) "User Does Not Exist"

var_dump($row) is spitting out:

array(2) { 'username' => string(15) "hossthebossross" 'password' => string(6) "654321" } and $userPasswords 

was : before
$userPasswords = array(

'andrejbranch' => '123456',
'hossthebossross' => '654321',
);