public static function authenticate_user($email, $pwd)
 {
     global $database;
     $success = 0;
     $userobj = new User();
     $salt_test = $userobj->retrieve_salt($email);
     $pwd_og_hash = $userobj->retrieve_pwd_hash($email);
     $pwd_entered_hash = $userobj->better_crypt($pwd, $salt_test);
     if ($pwd_og_hash == $pwd_entered_hash) {
         $success = 1;
     }
     /*$sql="SELECT COUNT(*) FROM users where email='".$email."' AND pwd='".md5($pwd)."' LIMIT 1";
     		$result_set=$database->query($sql);
     		$result=$database->fetch_array($result_set);
     		if($result[0]!=0){
     			return true;
     		}else{
     			return false;
     		}*/
     if ($success == 1) {
         return true;
     } else {
         return false;
     }
 }