Forward button bypasses delay in photo album

Question

I am a novice with Flash Pro but took on the challenge of creating a slideshow for a website. I used Flash Pro CS5 and the Advanced Photo Album template. I fought it out for a while and searched around for information before eventually getting it to load the images and work as coded.
All went well and I published the .SWF and all the images to the site's root folder but whenever I click the 'forward' button it skips an image. The delay is set to 5 seconds but it would appear that the forward button bypasses the delay i.e. if I leave an image up for 3 seconds and then press the forward button, the next image will only display for 2 seconds before siwtching to the following one, despite the delay being set to 5. If I let it run automatically all the images follow the delay rule. I have included the code below. The only thing I have altered is the duration of the 'fade' transition from 0.25 to 1.
Note: I have had to embed the HTML not the .SWF as when embedding the .SWF on the site it brought up the flash element but none of the images. Not sure if this is having an effect on the coding.
Many thanks for any assistance
import fl.data.DataProvider;
import fl.events.ListEvent;
import fl.transitions.*;
import fl.controls.*;
// USER CONFIG SETTINGS =====
var secondsDelay:Number = 5;
var autoStart:Boolean = true;
var transitionOn:Boolean = true; // true, false
var transitionType:String = "Fade"; // Blinds, Fade, Fly, Iris, Photo, PixelDissolve, Rotate, Squeeze, Wipe, Zoom, Random
var hardcodedXML:String="<photos><image title='Rank Badges'>image1.png</image><image title='How It Works'>image2.png</image><image title='First Steps'>image3.png</image><image title='Brain Crank'>image4.png</image><image title='Natural Friendship'>image5.png</image><image title='Fire Hazard'>image6.png</image><image title='I Got This'>image7.png</image><image title='Magic Act'>image8.png</image><image title='Replay'>image9.png</image><image title='Samaritan'>image10.png</image><image title='No Tag Backs'>image11.png</image></photos>";
// END USER CONFIG SETTINGS
// DECLARE VARIABLES AND OBJECTS =====
var imageList:XML = new XML();
var currentImageID:Number = 0;
var imageDP:DataProvider = new DataProvider();
var slideshowTimer:Timer = new Timer((secondsDelay*1000), 0);
// END DECLARATIONS
// CODE FOR HARDCODED XML =====
imageList = XML(hardcodedXML);
fl_parseImageXML(imageList);
// END CODE FOR HARDCODED XML
// EVENTS =====
imageTiles.addEventListener(ListEvent.ITEM_CLICK, fl_tileClickHandler);
function fl_tileClickHandler(evt:ListEvent):void
    imageHolder.imageLoader.source = evt.item.source;
    currentImageID = evt.item.imgID;
playPauseToggle_mc.addEventListener(MouseEvent.CLICK, fl_togglePlayPause);
function fl_togglePlayPause(evt:MouseEvent):void
    if(playPauseToggle_mc.currentLabel == "play")
        fl_startSlideShow();
        playPauseToggle_mc.gotoAndStop("pause");
    else if(playPauseToggle_mc.currentLabel == "pause")
        fl_pauseSlideShow();
        playPauseToggle_mc.gotoAndStop("play");
next_btn.addEventListener(MouseEvent.CLICK, fl_nextButtonClick);
prev_btn.addEventListener(MouseEvent.CLICK, fl_prevButtonClick);
function fl_nextButtonClick(evt:MouseEvent):void
    fl_nextSlide();
function fl_prevButtonClick(evt:MouseEvent):void
    fl_prevSlide();
slideshowTimer.addEventListener(TimerEvent.TIMER, fl_slideShowNext);
function fl_slideShowNext(evt:TimerEvent):void
    fl_nextSlide();
// END EVENTS
// FUNCTIONS AND LOGIC =====
function fl_parseImageXML(imageXML:XML):void
    var imagesNodes:XMLList = imageXML.children();
    for(var i in imagesNodes)
        var imgURL:String = imagesNodes[i];
        var imgTitle:String = imagesNodes[i].attribute("title");
        imageDP.addItem({label:imgTitle, source:imgURL, imgID:i});
    imageTiles.dataProvider = imageDP;
    imageHolder.imageLoader.source = imageDP.getItemAt(currentImageID).source;
    title_txt.text = imageDP.getItemAt(currentImageID).label;
function fl_startSlideShow():void
    slideshowTimer.start();
function fl_pauseSlideShow():void
    slideshowTimer.stop();
function fl_nextSlide():void
    currentImageID++;
    if(currentImageID >= imageDP.length)
        currentImageID = 0;
    if(transitionOn == true)
        fl_doTransition();
    imageHolder.imageLoader.source = imageDP.getItemAt(currentImageID).source;
    title_txt.text = imageDP.getItemAt(currentImageID).label;
function fl_prevSlide():void
    currentImageID--;
    if(currentImageID < 0)
        currentImageID = imageDP.length-1;
    if(transitionOn == true)
        fl_doTransition();
    imageHolder.imageLoader.source = imageDP.getItemAt(currentImageID).source;
    title_txt.text = imageDP.getItemAt(currentImageID).label;
function fl_doTransition():void
    if(transitionType == "Blinds")
        TransitionManager.start(imageHolder, {type:Blinds, direction:Transition.IN, duration:0.25});
    } else if (transitionType == "Fade")
        TransitionManager.start(imageHolder, {type:Fade, direction:Transition.IN, duration:1});
    } else if (transitionType == "Fly")
        TransitionManager.start(imageHolder, {type:Fly, direction:Transition.IN, duration:0.25});
    } else if (transitionType == "Iris")
        TransitionManager.start(imageHolder, {type:Iris, direction:Transition.IN, duration:0.25});
    } else if (transitionType == "Photo")
        TransitionManager.start(imageHolder, {type:Photo, direction:Transition.IN, duration:0.25});
    } else if (transitionType == "PixelDissolve")
        TransitionManager.start(imageHolder, {type:PixelDissolve, direction:Transition.IN, duration:0.25});
    } else if (transitionType == "Rotate")
        TransitionManager.start(imageHolder, {type:Rotate, direction:Transition.IN, duration:0.25});
    } else if (transitionType == "Squeeze")
        TransitionManager.start(imageHolder, {type:Squeeze, direction:Transition.IN, duration:0.25});
    } else if (transitionType == "Wipe")
        TransitionManager.start(imageHolder, {type:Wipe, direction:Transition.IN, duration:0.25});
    } else if (transitionType == "Zoom")
        TransitionManager.start(imageHolder, {type:Zoom, direction:Transition.IN, duration:0.25});
    } else if (transitionType == "Random")
        var randomNumber:Number = Math.round(Math.random()*9) + 1;
        switch (randomNumber) {
            case 1:
                TransitionManager.start(imageHolder, {type:Blinds, direction:Transition.IN, duration:0.25});
                break;
            case 2:
                TransitionManager.start(imageHolder, {type:Fade, direction:Transition.IN, duration:1});
                break;
            case 3:
                TransitionManager.start(imageHolder, {type:Fly, direction:Transition.IN, duration:0.25});
                break;
            case 4:
                TransitionManager.start(imageHolder, {type:Iris, direction:Transition.IN, duration:0.25});
                break;
            case 5:
                TransitionManager.start(imageHolder, {type:Photo, direction:Transition.IN, duration:0.25});
                break;
            case 6:
                TransitionManager.start(imageHolder, {type:PixelDissolve, direction:Transition.IN, duration:0.25});
                break;
            case 7:
                TransitionManager.start(imageHolder, {type:Rotate, direction:Transition.IN, duration:0.25});
                break;
            case 8:
                TransitionManager.start(imageHolder, {type:Squeeze, direction:Transition.IN, duration:0.25});
                break;
            case 9:
                TransitionManager.start(imageHolder, {type:Wipe, direction:Transition.IN, duration:0.25});
                break;
            case 10:
                TransitionManager.start(imageHolder, {type:Zoom, direction:Transition.IN, duration:0.25});
                break;
    } else
        trace("error - transitionType not recognized");
if(autoStart == true)
   fl_startSlideShow();
   playPauseToggle_mc.gotoAndStop("pause");
// END FUNCTIONS AND LOGIC

Answer 1

Yes, declared the var transition:Class
The error it gives now is:
TypeError: Error #1009: Cannot access a property or method of a null object reference.
          at flash_rank_fla::MainTimeline/fl_parseImageXML()
          at flash_rank_fla::MainTimeline/frame1()
The template is in Flash Professional CS5. New/Templates/Media Playback/Advanced Photo Album.
I will admit this is all alien to me but I suppose this is the par for the course - trial and error.
I am tempted to abandon this and go with something simpler but I was looking for the ability to pause the slide show and move froward/backward between images independant of the timer.
This is the code as it stands
import fl.data.DataProvider;
import fl.events.ListEvent;
import fl.transitions.*;
import fl.controls.*;
import flash.events.MouseEvent;
import flash.events.TimerEvent;
import flash.utils.Timer;
// USER CONFIG SETTINGS =====
var secondsDelay:Number = 5;
var autoStart:Boolean = true;
var transitionOn:Boolean = true; // true, false
var transitionsList:Object = {Blinds: Blinds, Fade: Fade, Fly: Fly, Iris: Iris, Photo: Photo, PixelDissolve: PixelDissolve, Rotate: Rotate, Rotate: Rotate, Squeeze: Squeeze, Wipe: Wipe, Zoom: Zoom};
var randomTransitions:Array = [Blinds, Fade, Fly, Iris, Photo, PixelDissolve, Rotate, Squeeze, Wipe, Zoom];
var transitionType:String = "Fade"; // Blinds, Fade, Fly, Iris, Photo, PixelDissolve, Rotate, Squeeze, Wipe, Zoom, Random
var imageList:XML = new XML(<photos><image title='Rank Badges'>image1.png</image><image title='How It Works'>image2.png</image><image title='First Steps'>image3.png</image><image title='Brain Crank'>image4.png</image><image title='Natural Friendship'>image5.png</image><image title='Fire Hazard'>image6.png</image><image title='I Got This'>image7.png</image><image title='Magic Act'>image8.png</image><image title='Replay'>image9.png</image><image title='Samaritan'>image10.png</image><image title='No Tag Backs'>image11.png</image></photos>);
fl_parseImageXML(imageList);
// END USER CONFIG SETTINGS
// DECLARE VARIABLES AND OBJECTS =====
var _currentImageID:Number = 0;
var imageDP:DataProvider = new DataProvider();
var slideshowTimer:Timer = new Timer((secondsDelay * 1000));
slideshowTimer.addEventListener(TimerEvent.TIMER, fl_slideShowNext);
// END DECLARATIONS
// EVENTS =====
imageTiles.addEventListener(ListEvent.ITEM_CLICK, fl_tileClickHandler);
next_btn.addEventListener(MouseEvent.CLICK, fl_nextButtonClick);
prev_btn.addEventListener(MouseEvent.CLICK, fl_prevButtonClick);
playPauseToggle_mc.addEventListener(MouseEvent.CLICK, fl_togglePlayPause);
function fl_tileClickHandler(e:ListEvent):void
    imageHolder.imageLoader.source = e.item.source;
    currentImageID = e.item.imgID;
function fl_togglePlayPause(e:MouseEvent):void
    if (playPauseToggle_mc.currentLabel == "play")
        fl_startSlideShow();
        playPauseToggle_mc.gotoAndStop("pause");
    else if (playPauseToggle_mc.currentLabel == "pause")
        fl_pauseSlideShow();
        playPauseToggle_mc.gotoAndStop("play");
function fl_nextButtonClick(e:MouseEvent):void
    fl_pauseSlideShow();
    fl_nextSlide();
function fl_prevButtonClick(e:MouseEvent):void
    fl_pauseSlideShow();
    fl_prevSlide();
function fl_slideShowNext(e:TimerEvent):void
    fl_nextSlide();
// END EVENTS
// FUNCTIONS AND LOGIC =====
function fl_parseImageXML(imageXML:XML):void
    var imagesNodes:XMLList = imageXML.children();
    for (var i:String in imagesNodes)
        imageDP.addItem({label: imagesNodes[i].@title, source: imagesNodes[i], imgID: int(i)});
    imageTiles.dataProvider = imageDP;
    imageHolder.imageLoader.source = imageDP.getItemAt(currentImageID).source;
    title_txt.text = imageDP.getItemAt(currentImageID).label;
function fl_startSlideShow():void
    slideshowTimer.start();
function fl_pauseSlideShow():void
    slideshowTimer.stop();
function fl_nextSlide():void
    currentImageID++;
function fl_prevSlide():void
    currentImageID--;
function get currentImageID():Number
    return _currentImageID;
function set currentImageID(value:Number):void
    _currentImageID = value < 0 ? imageDP.length - 1 : value;
    _currentImageID = value >= imageDP.length ? 0 : value;
    imageHolder.imageLoader.source = imageDP.getItemAt(_currentImageID).source;
    title_txt.text = imageDP.getItemAt(_currentImageID).label;
    if (transitionOn)
        fl_doTransition();
function fl_doTransition():void
    var transition:Class;
    var duration:Number = .25;
    if (transitionType == "Random")
        transition = randomTransitions[int(randomTransitions.length * Math.random())] as Class;
        duration = transition == Fade ? 1 : duration;
    else
        transition = transitionsList[transitionType] as Class;
        if (!transition)
            return;
    TransitionManager.start(imageHolder, {type: transition, direction: Transition.IN, duration: duration});
if (autoStart)
    fl_startSlideShow();
    playPauseToggle_mc.gotoAndStop("pause");
// END FUNCTIONS AND LOGIC