Scrolling based on mouse position quest

1

I have a playlist on the stage in a movieClip which is masked by a mask so that only a small portion is visible.

I have added a scroll function to that movieClip so that is scrolls up and down (with restrains ofcourse) based on my mouseY position on the stage.

Now, I found this formula for scrooling once somewhere else and it works fine…

container.y += Math.cos((-root.mouseY/stage.stageHeight)*Math.PI)*15;

…or it can be written this way ofcourse to scroll from side to side:

fullContainer.x += Math.cos((-root.mouseX/stage.stageWidth)*Math.PI)*15;

…and that number (15) repersents the speed of a scroll.

I have used this formula couple of times on some galleries i have created and it works just fine, but the content which is being applied to scroolls regardless the mouse is above the content we want to scroll or anywhere on the stage, BUT I wanted to create what has been created here, on this site: http://www.flashden.net/files/55697/index.html

when the home page opens, go down below to the right, there is a button for opening a playlist, and when the playlist opens on the center of the stage, this playlist can also be scrolled up and down based on the mouse position, BUT it ONLY scrolls when the mouse IS ABOVE the playlist, and anywhere else it doesnt scroll and there is a message: “close playlist”
now, what I am interested in is how to make this scrollable only when mouse is above the content we want to scroll.

If someone can enlighten me I would be greatly satisfied :stuck_out_tongue:

fullContainer.addEventListener(Event.ENTER_FRAME, cosinus);
function cosinus(e:Event) {
fullContainer.y += Math.cos((-root.mouseY/stage.stageHeight)*Math.PI)*15;

if (fullContainer.y > 0) { // the restrains
    fullContainer.y = 0;
}
if (fullContainer.y < - 300) { // the restrains
    fullContainer.y = - 300;
}

}

sorry for the long post and Happy New Year everyone!