Hi folks, I've been working on a problem for a couple of days and I can't crack it... so HELP (please)

I have a dynamically applied UIScrollBar that I would like to manipulate in terms of colours, ie. background slide and arrows etc. Judging by the literature out there I can use FStyleFormat... but when I look in the Flash help files there is no mention of 'FStyleFormat' So does that mean that it has no functionality in my version (CS3)?

The (useless) code I'm using is:

Code:
// changing the text scroller properties  \\
myStyle = new FStyleFormat();
myStyle.addListener(UIScrollBar);
myStyle.background = 0x00ff00;
myStyle.arrow = 0xFF0000;
myStyle.face = 0xFF0000;
myStyle.applyChanges();
But this has no effect on the (dynamic) UIScrollBar (which works fine)

Code:
this.createClassObject(mx.controls.UIScrollBar,"my_sb",20);

// Set the target text field for the scroll bar.
my_sb.setScrollTarget(dyn_txt);

// Size it to match the text field.
my_sb.setSize(16,dyn_txt._height);

// Move it next to the text field.
my_sb.move(dyn_txt._x+dyn_txt._width,dyn_txt._y);
Anyone got any ideas?