mysql - PHP set cookie not being set -

here code, know sql returning result because have checked. set cookie not seem working.

 public function login($username, $password){       $username = $_post['username'];     $password = md5($_post['password'].theme_salt);      global $wpdb;      $result = $wpdb->get_row( "select * {$wpdb->prefix}users username ='".$username."' , password ='" .$password."' limit 1");      if (!empty($result)){          setcookie("user", $username, time() + 3600);     }         return false; } 

any ideas?

try adding path

`setcookie("user", $username, time() + 3600, '/');`