Hi Rick, it looks like you're on the right track, but you're having trouble targeting your textbox correctly (see here and here for more info on targeting and scope).

Let's assume your setup is like this:
[main timeline] contains [movieClip named 'input_text'] contains [textfield named 'nam']

(and when I say named, obviously I mean the instance name of the object, as shown in the properties window)

So if you want to target the contents of the textfield from the main timeline you can say:
Code:
input_text.nam.text="NAME";
(ie set the text property of the 'nam' textfield in 'input_text' to "NAME")

And if you want to set an onSetFocus action for 'nam' from the first frame of the 'input_text' movie, you can say:
Code:
nam.onSetFocus = function() {
    nam.text = "";
}
I've tested this, and it works - but perhaps my flash file is set up differently to yours?
Anyway, if you need more help on this, go back to stackoverflow and edit your question from yesterday...