code in frame 1 don't want to work in frame 10, app goes wacko

I am still using Flash CS3.

I have several buttons in frame one and used the following actionscript which works fine

CODE:

stop();

function handleClick( pEvent:MouseEvent ):void

{

          if( pEvent.target == eat_btn )

          {

                    gotoAndStop(10);

          }

          if( pEvent.target == family_btn )

          {

                    gotoAndStop(20);

          }

          if( pEvent.target == learn_btn )

          {

                    gotoAndStop(30);

          }

          if( pEvent.target == toy_btn )

          {

                    gotoAndStop(40);

          }

}

eat_btn.addEventListener(

MouseEvent.CLICK, handleClick );

family_btn.addEventListener(

MouseEvent.CLICK, handleClick );

learn_btn.addEventListener(

MouseEvent.CLICK, handleClick );

toy_btn.addEventListener(

MouseEvent.CLICK, handleClick );

untill I want to use the same coding for my back_btn in frame 10 through 80, my whole application goes wacko!

CODE FOR BACK BUTTON USED IN FRAME 10

stop();

function handleClick( pEvent:MouseEvent ):void

{

          if( pEvent.target == back_btn )

          {

                    gotoAndStop(1);

          }

}

back_btn.addEventListener(

MouseEvent.CLICK, handleClick );

Can some one please help explain this, and what I should do to fix this?

Thanks