Simple slideshow, will not work in as 3.0

Question

L.S. I have this little slideshow, it is for practise for my students. It always worked well in as 2.0,
5 slides, and two buttons: back and next.
The script in2.0 has: prevFrame and nextFrame in the code
and for the exceptions in frame 1, and frame 5 we made a new frame 1 in the actions layer, and coded the back button, gotoAndStop(5); and a new frame 5, and coded the next button: gotoAndStop(1);
Works.
Now I put the thing over tot as 3.0: And I can not get it to work properly....the buttons work, but when I am on frame 5, and go back to 4, it will go no further than 4, evenso when I go back to frame 1 from 5, I can not go further up than frame 1.
What do I do wrong??
attached is the fla in cs5.
Thanks,
Anne Vossen
Message was edited by: Vossen I am sorry but I can not find the button to load up my files...so here is the script:
as frame 1:
import flash.events.MouseEvent;
stop();
next_btn.addEventListener(MouseEvent.CLICK, volgendFrame);
//next_btn.addEventListener(MouseEvent.CLICK, eersteFrame);
//back_btn.addEventListener(MouseEvent.CLICK, vorigFrame);
back_btn.addEventListener(MouseEvent.CLICK, laatsteFrame);
function volgendFrame(evt:MouseEvent):void{
nextFrame();
function eersteFrame(evt:MouseEvent):void{
gotoAndStop(1);
function vorigFrame(event:MouseEvent):void{
prevFrame();
function laatsteFrame(event:MouseEvent):void{
gotoAndStop(5);
frame 2:
next_btn.addEventListener(MouseEvent.CLICK, volgendFrame);
//next_btn.addEventListener(MouseEvent.CLICK, eersteFrame);
back_btn.addEventListener(MouseEvent.CLICK, vorigFrame);
//back_btn.addEventListener(MouseEvent.CLICK, laatsteFrame);
frame 5:
stop();
//next_btn.addEventListener(MouseEvent.CLICK, volgendFrame);
next_btn.addEventListener(MouseEvent.CLICK, eersteFrame);
back_btn.addEventListener(MouseEvent.CLICK, vorigFrame);
//back_btn.addEventListener(MouseEvent.CLICK, laatsteFrame);

Answer 1

It will be easiest to manage if you just have the buttons coded once for the entire timeline with the special conditions written into the functions instead of switching listeners.  And if you use totalFrames instead of the actual number (5), you can add frames in the future without having to change the code...  Frame 1...
stop();
next_btn.addEventListener(MouseEvent.CLICK, volgendFrame);
back_btn.addEventListener(MouseEvent.CLICK, vorigFrame);
function volgendFrame(evt:MouseEvent):void{
    if(currentFrame < totalFrames){
         nextFrame();
    } else {
         gotoAndStop(1);
function vorigFrame(event:MouseEvent):void{
    if(currentFrame > 1){
         prevFrame();
    } else {
         gotoAndStop(totalFrames);