AS3中的错误1046。 3个简单的按钮，没有用？

Question

I'm trying to make a simple start up screen for a game i'm making, and I put a button (Backbtn)on Frame 2, to go back to frame 1, but nothing works, it just flies through the frames, the Stop(); doesn't work, and I keep getting error 1046: Type was not found or was not a compile-time constant: Backbtn.

Any help, this is my code!

 import flash.events.MouseEvent;

 stop();

HTP.addEventListener(MouseEvent.CLICK, goClick);
PlayButton.addEventListener(MouseEvent.CLICK, goPlay);
Backbtn.addEventListener(MouseEvent.CLICK, goBack);

function goClick(event:MouseEvent): void 
{
trace("two");
    gotoAndStop(2);
}

function goPlay(event:MouseEvent): void
{
    trace("three");
gotoAndStop(3);
}

function goBack(event:MouseEvent) : void
{
trace("TEST");
gotoAndStop(1);
}

Thank you!

Answer 1

What's wrong with my code?

BackBtn isn't defined until frame 2, therefore it is undefined until frame 2.

Oh noes! How do I fix this?

Change your code to:

 import flash.events.MouseEvent;

 stop();

HTP.addEventListener(MouseEvent.CLICK, goClick);
PlayButton.addEventListener(MouseEvent.CLICK, goPlay);

function goClick(event:MouseEvent): void 
{
trace("two");
    gotoAndStop(2);
}

function goPlay(event:MouseEvent): void
{
    trace("three");
gotoAndStop(3);
}

And put this code on frame 2:

Backbtn.addEventListener(MouseEvent.CLICK, goBack);
function goBack(event:MouseEvent) : void
{
    trace("TEST");
    gotoAndStop(1);
}