MOUSE_OVER/MOUSE_OUT - txt.visible=true/false;

Question

I have a small problem with MOUSE_OVER, MOUSE_OUT event. On this map(MovieClip) I have 3 points(buttons) and when you will put a mouse cursor over one of them, in a space on the left sites will appear an address (difrent for all of buttons).
1º I have buttons with instance names on the stage (qlu_btn, mad_btn, are_btn)
2º In my library I have my text(address) - I transformed it in a symbol (MovieClip) and I assigned the instance names (qlu_txt, mad_txt, are_txt) in proprties.
This is my AS3 for this movieClip for 1º of the buttons... but it doesn't works... Any idea where is a problem????
var mad_txt:MovieClip = new MovieClip;
addChild(mad_txt);
mad_txt.x = - 140.0;
mad_txt.y = - 65.0;
mad_txt.visible = false;
mad_btn.addEventListener(MouseEvent.MOUSE_OVER, gotoMadridOver);
mad_btn.addEventListener(MouseEvent.MOUSE_OUT, gotuMadridOut);
function gotoMadridOver(event:MouseEvent):void{
     mad_txt.visible = true;
function gotoMadridOut(event:MouseEvent):void{
     mad_txt.visible = false;

Answer 1

The code probably works but it's only an empty MovieClip, so you won't see it and won't be able to interact with it.  All that the following line does is create an empty MovieClip object named mad_txt.  It will have no relation to anything else you have done.
var mad_txt:MovieClip = new MovieClip;