Simple code problem,need fresh eyes

1

how do i know its simple…i dunno but knowing me…its pretty stupid and probably right under my nose…

im studying AS3 (after a long hiatus and trying to get back to flash)

so im doing this small site to test myself and while declaring my buttons (code below) i get a 1099 error saying

TypeError: Error #1009: Cannot access a property or method of a null object reference.
at main_fla::MainTimeline/frame1()

i have no idea what this means.

heres ALL i have on frame one so far.

import flash.events.MouseEvent;
import flash.ui.Mouse;
import flash.net.URLRequest;

//MY BUTTON declarations. THEIR LISTENERS AND THEIR FUNCTIONS below.

aboutBtn.addEventListener(MouseEvent.CLICK,aboutbtn);
function aboutbtn(e:MouseEvent):void
{
	gotoAndPlay("about");
}

contactBtn.addEventListener(MouseEvent.CLICK,contactbtn);
function contactbtn(e:MouseEvent):void
{
	gotoAndPlay("contact");
}

portfolioBtn.addEventListener(MouseEvent.CLICK,portfoliobtn);
function portfoliobtn(e:MouseEvent):void
{
	gotoAndPlay("portfolio");
}

homeBtn.addEventListener(MouseEvent.CLICK,homebtn);
function homebtn(e:MouseEvent):void
{
	gotoAndPlay("home");
}

followMeBtn.addEventListener(MouseEvent.CLICK,followmebtn);
function followmebtn(e:MouseEvent):void
{
	navigateToURL(new URLRequest("http://www.twitter.com/somdow"), "_blank");
}

// Btns in the port section.



port2ImgBtn.addEventListener(MouseEvent.CLICK,port2imgbtn);
function port2imgbtn(e:MouseEvent):void
{
	trace("btn clicked");
}

port1ImgBtn.addEventListener(MouseEvent.CLICK,port1imgbtn);
function port1imgbtn(e:MouseEvent):void
{
	trace("btn clicked lol");
}

any ideas??? im lost