Hi all

Consider a progress bar which supposed to indicate a quality for instance.

How can I get a three state thing which states that this progress bar is fixed, increasing or decreasing?
In mathematics there's a way in which you calculate differences between current x(t) and its one step retard x(t-1). I wasn't successful to get my previous progress bar value due to "value change" event is not available for this control.

If anyone know a trick to rectify this matter I will be so much appreciated. ♥ Thanks in advanced