[Nirth]

import mx.controls.Button;
import mx.controls.CheckBox;

var checkBoxes:Array = new Array();
var button:mx.controls.Button;

function changeCheckBoxValue(event:Object):Void
{
    var maximum:Number = checkBoxes.length;
    var index:Number   = Math.floor(Math.random() * maximum);
	
    var cb:CheckBox = CheckBox(checkBoxes[index]);
        cb.selected = (cb.selected) ? false : true;
}

function createGUI():Void
{
    for ( var i:Number = 0; i < 5; i ++)
    {
        checkBoxes.push(createClassObject(CheckBox, "cb" + i.toString(),
                                          getNextHighestDepth(),
                                          {_y: i * 23, label: "cb "+ i.toString()} ));
    }
	
    button = createClassObject(mx.controls.Button, "button",
                               getNextHighestDepth(),
                               {_y: 6 * 23, _width: 140, label: "Change ChechBox"});
    button.addEventListener("click", changeCheckBoxValue);
}

createGUI();

Так?