Addressing instances in external swf's

1

I have a external swf that loads into a target movie in my main swf. The external swf contains components and dynamic text boxes.

How do I address these from within the main swf???

Say we have an dynamic text box in the external swf called txtBox.

I want to populate this txt box from within a function which exists in the main swf… I’ve tried _parent, _root and _level10 (which is where the external movie seems to load into.

function myFunc() {
++something here?++txtBox.text=“help!”;
}