function getBodySize() {

        var w = window,
        d = document,
        e = d.documentElement,
        g = d.getElementsByTagName('body')[0],
        x = w.innerWidth || e.clientWidth || g.clientWidth,
        y = w.innerHeight|| e.clientHeight|| g.clientHeight;

        if (x != Body_W || y != Body_H) {
            Body_W = x;
            Body_H = y;
            resizeCanvas();
        }
    }

    function resizeCanvas() {
        var new_canvas_W = W;
        var new_canvas_H = H;

        if (W > Body_W || H > Body_H) {
            new_canvas_W = Body_W;
            new_canvas_H = H / 1024 * Body_W;

            if (H > Body_H) {
                new_canvas_W =  W / 720 * Body_H ;
                new_canvas_H = Body_H;
            }
        }

        if (new_canvas_W != canvas.width  || new_canvas_H != canvas.height) {
            canvas.width  = new_canvas_W;
            canvas.height = new_canvas_H;
        }

        stage.scaleX = new_canvas_W / 1024;
        stage.scaleY = new_canvas_H / 720;

        stage.update();
    }