Unload SWF.

Question

I recieved some help earlier with actionscript 3.0 and buttons. I wanted my buttons to load in a swf file into the main flash document when clicked. I can't seem to figure out how to get multiple swfs files loaded into the flash document. I also need the swf files to unload when an diffrenent buttons is clicked.
var myMenuArray: URLRequest = new URLRequesr["we.swf","port.swf"]:
for each (var btn in myMenuArray){
    btn.addEventListener(MouseEvent.CLICK, onbtnClick);
function onbtnClick (event:MouseEvent):void{
    pages.gotoAndStop(event.target.name);
var ldr:Loader = new Loader();
we_btn.addEventListener(MouseEvent.CLICK, weClick);
function weClick (event:MouseEvent) {
ldr.load(urlReq);
addChild(ldr)

Answer 1

Ok, it has taken me sometime (roughly 4 hours) to load the swf with each button. I created a movieclip with the instance name of ldr to match the loader code in action script. When the movieclip has an intance name of ldr I recieve this error
TypeError: Error #1034: Type Coercion failed: cannot convert flash.display::MovieClip@1db47061 to flash.display.Loader.
    at flash.display::Sprite/constructChildren()
    at flash.display::Sprite()
    at flash.display::MovieClip()
    at index_fla::MainTimeline()
However, if I don't use the moviclip the swf files will be placed in the upper left hand corner of the stage. Why is this?
this is the link to my website I don't have the current code below updated to the server yet(http://studio-5-design.net/index.html).
A critique of my site will also help me. I am an architecture student and I am creating a site to display my school projects along with a portfolio
modified code
var ldr:Loader = new Loader();
////////////Home Button///////////////////////////////////////
var homeReq:URLRequest=new URLRequest("_swf/home.swf");
home_btn.addEventListener(MouseEvent.CLICK, homeClick);
function homeClick(event:MouseEvent) {
    ldr.load(homeReq);
    addChild(ldr);
////////////We Are Button///////////////////
var weReq:URLRequest=new URLRequest("_swf/we.swf");
we_btn.addEventListener(MouseEvent.CLICK, weClick);
function weClick(event:MouseEvent) {
    ldr.load(weReq);
    addChild(ldr);
////////////Portfolio Button////////////////////////////////////////////////
var portReq:URLRequest=new URLRequest("_swf/port.swf");
port_btn.addEventListener(MouseEvent.CLICK, portClick);
function portClick(event:MouseEvent) {
    ldr.load(portReq);
    addChild(ldr);
/////////////Reflections Button/////////////////////////////////////////////
var reflReq:URLRequest=new URLRequest("_swf/reflection.swf");
reflec_btn.addEventListener(MouseEvent.CLICK, reflClick);
function reflClick(event:MouseEvent) {
    ldr.load(reflReq);
    addChild(ldr);