Flash as3 remoting + amfphp Exercise 1

After searching a lot of information on the Internet, I finally started programming.
Flash remoting with as3 by: Jorge Solis this article is good. I decided to start from it, and sourcecode is very suitable for someone who has no experience with flash.
When I did the first exercise loading/saving data using amfphp, I encountered two problems:

1. Flash is created based on the example, and compilation fails.
Source: 34 rows, trace ("there was a problem:" + F. Description );
Description: 1119: access the undefined attribute description (referenced by the static type flash. Events: event ).
Then change to f.tar get. description. The example does not have this problem. It is speechless...

2. Incorrect PHP File Location
Remember to make a PHP file: 1) the file name is the same as the class name; 2) the file must be placed under // localhost/amfphp/services.