A problem with accessing the public variable inside the function

Question

Hi,
I have got this package and I get error 1120: 1120: Access of undefined property aa
Could you explain why I get this error?
package somepackage {
    import flash.display.DisplayObject;
    import mx.containers.Canvas;
    public class SoundPictureSigns extends Canvas {
        public var aa:int = 12;
        public function SoundPictureSigns():void {
        public static function setUpSignSizes():void {
            trace("aa="+aa); /// ERROR here: 1120: Access of undefined property aa
Can you help?
Regards

Answer 1

When you write
class C
    var v;
you are defining a variable that lives inside each instance of C. In other words, you can write code like
var c:C = new C();
c.v = 1;
If you don't have an instance, you can't access v.
When you write
class C
    static var v;
you are defining a variable that lives inside the class itself, and you can access it without having an instance.
Gordon Smith
Adobe Flex SDK Team