Scoll panel zooming

Question

I want to add zoom feature to the scroll panel. As the zoom
button is pressed, I have to increase scrolling area. I tried the
following sample code. If you run the sample, you can see the image
size is increasing, but the scrolling area is same. I want to
dynamically change the scrolling area according to image size. How
can I do that?
this.createClassObject(mx.containers.ScrollPane, "my_sp",
10);
my_sp.setSize(360, 280);
System.security.allowDomain("
http://www.helpexamples.com");
my_sp.contentPath = "
http://www.helpexamples.com/flash/images/image1.jpg";
my_sp.scrollDrag = true;
var width_num=my_sp._width;
var height_num=my_sp._height;
my_btn.onPress = function()
trace(width_num);
width_num += 100.0;
height_num += 100.0;
my_sp.content.setSize(width_num, height_num);
};

Answer 1

I fount the solution. It's to set the scrollpolicy off before
the resize and on after that.
fmy_sp.hScrollPolicy = "on";
my_sp.vScrollPolicy = "on";