here are some other solutions for you:

Method 1 (quick but dirty): you can put function IN the event listener:
PHP Code:
Button1.addEventListener(MouseEvent.CLICK, function(e:MouseEvent){ gotoAndStop("FrameLabel1");} , false0true);
Button2.addEventListener(MouseEvent.CLICK, function(e:MouseEvent){ gotoAndStop("FrameLabel2");} , false0true); 
Method 2 (longer but a lil cleaner): create a variable in the button for you to access

PHP Code:
// Add listeners to buttons
var Button1:YourSpecialButtonClass;
var 
Button2:YourSpecialButtonClass;

Button1.frameLabelTarget 'FrameLabel1';
Button1.addEventListener(MouseEvent.CLICKNavigatefalse0true);

Button2.frameLabelTarget 'FrameLabel2';
Button2.addEventListener(MouseEvent.CLICKNavigatefalse0true);

// Define the Navigate function
function Navigate(evt:MouseEvent):void{
    
gotoAndStop( (evt.currentTarget as YourSpecialButtonClass).frameLabelTarget );