How do I convert this to ActionScript 2.0?

I’ve come across this image gallery code in Actionscript 3.0 and I’m wondering how this can be rewritten in AS2…
Any idea how?
(The code are to be inserted in certain frames, hence the reference to frame numbers…)

//AS3 Code (1st Frame)
var nextImage:Timer = new Timer(2000);
nextImage.addEventListener(TimerEvent.TIMER, playNext);
nextImage.start();

function playNext(event:Event):void{
nextFrame();
}

//AS3 Code (2nd Frame)
stop();
//////////////////////////////////////////////////////////////////
btn1.addEventListener(MouseEvent.CLICK,play1);

function play1(event:MouseEvent):void{
nextImage.stop();
gotoAndStop(2);
btn1.addEventListener(MouseEvent.ROLL_OUT, rollout);

function rollout(event:MouseEvent):void{
	nextImage.reset();
	nextImage.start();

}

}
//////////////////////////////////////////////////////////////////
btn2.addEventListener(MouseEvent.CLICK,play2);

function play2(event:MouseEvent):void{
nextImage.stop();
gotoAndStop(3);
btn2.addEventListener(MouseEvent.ROLL_OUT, rollout);

function rollout(event:MouseEvent):void{
	nextImage.reset();
	nextImage.start();

}

}

btn3.addEventListener(MouseEvent.CLICK,play3);

function play3(event:MouseEvent):void{
nextImage.stop();
gotoAndStop(4);
btn3.addEventListener(MouseEvent.ROLL_OUT, rollout);

function rollout(event:MouseEvent):void{
	nextImage.reset();
	nextImage.start();

}

}

btn4.addEventListener(MouseEvent.CLICK,play4);

function play4(event:MouseEvent):void{
nextImage.stop();
gotoAndStop(5);
btn4.addEventListener(MouseEvent.ROLL_OUT, rollout);

function rollout(event:MouseEvent):void{
	nextImage.reset();
	nextImage.start();

}

}

//AS3 Code (Last Frame)
nextImage.stop();
nextImage.reset();
gotoAndPlay(1);

Change the bits that use apis unique to as3, into their equivalents in as2
e.g
timer -> setinterval