casting from FLEX to PHP

AS3 code

<fx:Declarations>
    <!-- this is the RemoteObject  used to make the RPC calls -->
    <mx:RemoteObject id="myRemote" destination="MyService" source="MyService"
       endpoint="http://localhost/amfphp/gateway.php"                
            showBusyCursor="true"/>

</fx:Declarations>

protected function button1_clickHandler(event:MouseEvent):void
{
    var aut:VOAuthor;  // value object class
    aut = new VOAuthor();
    aut.id_aut = 3;
    aut.fname_aut = "test";
    aut.lname_aut = "123";
    myRemote.saveData(aut);
}

Receving PHP code

public function saveData($author) 
{
   $mysql = mysql_connect("localhost", "mx112", "xxxxxx");          
   mysql_select_db("flex360");      
   $query = "INSERT INTO authors (fname_aut, lname_aut) VALUES ('".$author->fname_aut."', '".$author->lname_aut."')";          
   $result = mysql_query($query);                 
   return $author;
}


<?php
class VOAuthor {   
 public $id_aut;    
 public $fname_aut;    
 public $lname_aut;        
 var $_explicitType="org.corlan.VOAuthor";}
?>

Flex network monitor response : Raw view

{lname_aut=123, _explicitType=org.corlan.VOAuthor, fname_aut=test, id_aut=3}

but If I do this at the end of the php code

 return $author->lname_aut;

network monitor response is NULL

so the problem is I can print the array but how to cast tht array to a known php type ? After 5 days I finnaly figured out flex and mysql using amfphp any one please help ?

if you are using amfphp and Flash you have to register your VOs:

import org.corlan.VOAuthor;
// ...
registerClassAlias("org.corlan.VOAuthor", VOAuthor);

only then does php recognize the objects you're sending it from ActionScript.