Accessing a class private variable in the main timeline

Question

Greetings,
noob question.
Here's my main class:
package
     import flash.external.ExternalInterface;
     public class main
         public function main()
         public function check_DVBViewer()
             ExternalInterface.call("check_DVBViewer","test");
             ExternalInterface.addCallback("AutoIT",AutoIT);
         private function AutoIT(my_msg:String)
                 // here we get the callback string
in the timeline I have a dynamic text box named my_textbox:
var my_test:main = new main();
my_test.check_DVBViewer();
my_textbox.text = ???????
Basically the class waits for the callback variable (my_msg).
The problem is: I need to set the dynamic textbox text to my_msg variable.
How can I access it?
I know I can access a public var in the timeline with functioname.variable but I can't define a public var inside a function, right?
Thank you very much for your time.

Answer 1

dispatch an event when the string is ready:
package
     import flash.external.ExternalInterface;
     public class main
private var msg:String;
         public function main()
         public function check_DVBViewer()
             ExternalInterface.call("check_DVBViewer","test");
             ExternalInterface.addCallback("AutoIT",AutoIT);
         private function AutoIT(my_msg:String)
                 // here we get the callback string
msg=my_msg;
dispatchEvent(new Event("stringready"));
public function get msgF():String{
return msg;
in the timeline I have a dynamic text box named my_textbox:
var my_test:main = new main();
my_test.addEventListener("stringready",f);
my_test.check_DVBViewer();
function f(e:Event):void{
my_textbox.text = my_test.msgF;