Trying to create a small Image Gallery in Action Script

Trying to create a small Image Gallery in Action Script

I'm new to Flash and AS3 and I'm trying to make an image gallery. For some reason it .. doesn't do anything.
I have 2 buttons: back & next and a Dynamic Text field for loading progress. zonaAfisare_mc is the container for the images. It doesn't load any image, here's the code:
import flash.events.*;
import flash.display.*;
import flash.net.*;

var source:*;
var loader:Loader;
var loaderIndex:Number = 1;

next.addEventListener(MouseEvent.CLICK, loadNext);
back.addEventListener(MouseEvent.CLICK, loadPrev);

function loadIt()
    {

        loader = new Loader();
        loader.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS,onLoadingProgress);
        loader.contentLoaderInfo.addEventListener(Event.INIT,initHandler);         
        addChild(loader);          
        loadImage();
    }


function initHandler(event:Event):void
    {
        source = loader.content;
        source.alpha = 0;
        source.x = zonaAfisare_mc.x;
        source.y = zonaAfisare_mc.y;

        addEventListener(Event.ENTER_FRAME,enterFrameHandler);
    }
function onLoadingProgress(evt:ProgressEvent):void{
        var percentage:Number=(evt.bytesLoaded/evt.bytesTotal)*100;
        var total_percentage:Number=Math.floor(percentage);
        loaded.text=total_percentage.toString()+" %";
    }

function loadNext(event:Event):void
    {
        if (loaderIndex = 5) {
            loaderIndex = 1
            loadImage();
        } else {           
            loaderIndex = loaderIndex + 1;
            loadImage();
        }
    }
function loadPrev(event:Event):void
    {
        if (loaderIndex = 1) {
            loadImage();
        } else {
            loaderIndex = loaderIndex - 1;
            loadImage();
        }
    }



function enterFrameHandler(event:Event):void
    {
        if( source.alpha < 1 ){
            source.alpha += .1;
        }else{
            removeEventListener(Event.ENTER_FRAME,enterFrameHandler);
        }
    }

function getPath():String
    {
        return ("images/image"+loaderIndex+".jpg");
    }
function loadImage():void
    {
        loader.load(new URLRequest(getPath()));
    }
loadIt();