Calling variable set in Scene 1

Question

apologies for the repost/redo but previous did not work as I
thought it did!
I'm working with Scene 1 with 2 buttons, "Corporate" and
"Editorial" and a movie clip, mcMainScreenArea. I want the buttons
to set a variable which can be called in movie clip
mcMainScreenArea. This variable is then used in mcMainScreenArea
(and later also in another movie clip) to move the timeline along
to a label string set in the variable by the buttons in Scene 1.
With the following scripts the mcMainScreenArea simply plays
the timeline to the next clip - the variable does not appear to be
defined and a trace(this.varSubject); in the code returns
"undefined".
Code for Scene 1 is as follows.
stop();
//Navigation variables
var varSubject:String = "opening";
gotoAndStop(varSubject);
trace(varSubject);
function moveToCorporate(event:MouseEvent):void {
var varSubject:String = "corporate";
gotoAndStop(varSubject);
this.mcMainScreenArea.play();
trace(varSubject);
btn_corporate.addEventListener(MouseEvent.CLICK,
moveToCorporate);
function moveToEditorial(event:MouseEvent):void {
var varSubject:String = "editorial";
gotoAndStop(varSubject);
this.mcMainScreenArea.play();
trace(varSubject);
btn_editorial.addEventListener(MouseEvent.CLICK,
moveToEditorial);
The code for mcMainScreenArea is
stop(); //at labels named "corporate" and "editorial"
//and
gotoAndPlay(this.varSubject); //after the labels named
"corporate" and "editorial"

Answer 1

This I find surprising! No way of calling a variable set in
another element? Are there any alternatives to set a variable (or
whatever) to be read by mcMainScreenArea? Is there a way for
mcMainScreenArea to check what button has been clicked without
having the script in Scene 1 telling mcMainScreenArea what button
has been clicked. Pull rather than push the infor from the
button...
Thanks.