Get a random point on stage

1

hello all, i am trying to do somthing super simple but i just cant wrap my head around it.

i have a movieclip that is in the shape of a tree.

i need to get a random point on the tree. so i first get a random point on the stage, then i check if that point is over the tree (with hitTestPoint)

if it is then i return the point since i need the x and y coordinates to do something.

if not i need to get another point.

my problem is that i cant figure out how to get another one if my point is not valid. i did something like:

var point:Point = new Point ((Math.random () * _stageWidth), (Math.random () * _stageHeight));

if (_treeArea.hitTestPoint (point.x, point.y, true)) {
     return point;

    } else {
    // how do i get another one and redo the previous steps? i miss basic's GOTO LINE :(
}

maybe something recursive should be done? how?

2 
var point:Point = new Point ((Math.random () * _stageWidth), (Math.random () * _stageHeight));
while (_treeArea.hitTestPoint (point.x, point.y, true)) {
     return point;
}