Definition could not be found?

programming flash
1

Hello,

I’m just messing around in Flash and I’ve come across an error I could not fix.

1172: Definition fl.controls:ColorPicker could not be found.

This is the code for my ActionScript

import fl.controls.ColorPicker;

var cp:ColorPicker = new ColorPicker();
cp.colors = [ 0x001100, 
              0x003300, 
              0x005500, 
              0x007700, 
              0x009900, 
              0x00BB00, 
              0x00DD00, 
              0x00FF00 ];
addChild(cp);

This code comes from an example in the Flash-help, ColorPicker class.
It seems Flash can’t find the Colorpicker class (and as far as I know all classes that start with fl.). If this is the case, how can I fix this?