JSON Array in Flex

I have code:

api_result = '{"response":[开发者_StackOverflow社区{"uid":1969258,"first_name":"Walle","last_name":"Woo"}]}'; 
var myobj:Object = JSON.decode(api_result);

So, how I can get uid, first_name and last_name from "response" array?

var UID:Object = myobj.response[0].uid;

var firstName:Object = myobj.response[0].first_name;

var lastName:Object = myobj.response[0].last_name;