Flash Code for Buttons

The flash tutorial that Craig showed us gave us a code that enables symbols to turn into buttons:

stop();

btnDirect.addEventListener(MouseEvent.CLICK, buttonClickHandler);

function buttonClickHandler(event:MouseEvent):void

{

 trace("Button clicked!");

  MovieClip(root).gotoAndStop(MovieClip(root).currentFrame+1);

}

,

 I am definitely going to need to know how to do this as I require my interface to navigate through different screens, or I might need to show certain animations such as  zooming in on an area if map, this I can only do if I know how to create and use buttons.
So far I have not been able to create a successful button but I have been asking around like crazy for help. My fingers are crossed that somebody will know what to do, until then I will work on setting up my interface screens.