How to make on.Press from _level2 for a button thats on _level3 (AS2 - Flash 8 Pro)

Hi, **(AS2 - Flash 8 Pro)
**
My script on _level2 loads a swf webpage into _level3.
I also have a script on _level2 main timeline as follows…

_level3.returnBtn.onPress=function(){
loadMovieNum(“NoFile”,3);
};
**
Ive created a button with the correct instance name returnBtn in the swf
that loads into
* _level3***. Now after the swf loads correctly into _level3 and
it shows the ***returnBtn ***clip. Clicking on it does nothing. But the mouse over
is being sensed over it which proves the ***onPress ***is acting from the lower layer.

When i click this button i just wanted the swf which has loaded into _level3 to be flushed out with nothing. So i gave a non existant file name NoFile.swf.

But it does nothing.