I don't know why my buttons dont work?

I don't know why my buttons dont work?  When I click them nothing happens stays on the same page I bring up and I have them all in the same folder?

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

var homeURL:URLRequest = new URLRequest("Home.html");
var balingURL:URLRequest = new URLRequest("Baling.html");
var wrappingURL:URLRequest = new URLRequest("Wrapping.html");
var choppingURL:URLRequest = new URLRequest("Chopping.html");
var tillageURL:URLRequest = new URLRequest("Tillage.html");
var rakingURL:URLRequest = new URLRequest("Raking.html");
var contactURL:URLRequest = new URLRequest("Contact.html");

function homeURLDown(event:MouseEvent):void

{

navigateToURL(homeURL, "_self");

}

function balingURLDown(event:MouseEvent):void
{

navigateToURL(balingURL, "_self");

}

function wrappingURLDown(event:MouseEvent):void
{

navigateToURL(wrappingURL, "_self");

}

function choppingURLDown(event:MouseEvent):void
{

navigateToURL(choppingURL, "_self");

}

function tillageURLDown(event:MouseEvent):void
{

navigateToURL(tillageURL, "_self");

}

function rakingURLDown(event:MouseEvent):void
{

navigateToURL(rakingURL, "_self");

}

function contactURLDown(event:MouseEvent):void
{

navigateToURL(contactURL, "_self");

}

home_btn.addEventListener(MouseEvent.CLICK, homeURLDown);
baling_btn.addEventListener(MouseEvent.CLICK, balingURLDown);
wrapping_btn.addEventListener(MouseEvent.CLICK, wrappingURLDown);
chopping_btn.addEventListener(MouseEvent.CLICK, choppingURLDown);
tillage_btn.addEventListener(MouseEvent.CLICK, tillageURLDown);
raking_btn.addEventListener(MouseEvent.CLICK, rakingURLDown);
contact_btn.addEventListener(MouseEvent.CLICK, contactURLDown);