var photoView;
var captionBox;
var photoIndex = 0;
var photoImage;
var btnNext;
var btnPrev;
var photoArray = new Array();
var captionArray = new Array();
var imageLinksArray = new Array();

function LoadPhotoBox(){
			
	photoView = document.getElementById("photoLink");
	captionBox = document.getElementById("photoCaption");
	btnNext = document.getElementById("photoNext");
	btnPrev = document.getElementById("photoPrevious");
	
	if(photoView){
		photoImage = document.createElement("img");  
		photoImage.src = photoArray[photoIndex];
		photoImage.alt = "";
		photoImage.id = "imageItem";

		photoView.appendChild(photoImage);
		ToggleImage();
	}
}

function PhotoNext(){
	if(photoIndex < (photoArray.length - 1)){
		photoIndex++;
		ToggleImage();	
	}
	return false;
}

function PhotoPrevious(){
	
	if(photoIndex > 0){
		photoIndex--;
		ToggleImage();
	}
	return false;
}

function ToggleImage(){
	if(photoArray.length > 0){	
		photoImage.src = photoArray[photoIndex];
		if(imageLinksArray[photoIndex]){
			photoView.href = imageLinksArray[photoIndex]
		}
		ToggleCaption();
		toggleCountDisplay();
		ToggleControls();
	}
	
	return;
}

function ToggleControls(){
	if(btnNext && btnPrev){	
		if(photoIndex == 0){
			btnNext.src = "http://www.labour.org.nz/images/photobox_next_on.gif";
			btnPrev.src = "http://www.labour.org.nz/images/photobox_previous_off.gif";
		}
		else if(photoIndex == (photoArray.length -1)){
			btnNext.src = "http://www.labour.org.nz/images/photobox_next_off.gif"
			btnPrev.src = "http://www.labour.org.nz/images/photobox_previous_on.gif";
		}else{
			btnNext.src = "http://www.labour.org.nz/images/photobox_next_on.gif"
			btnPrev.src = "http://www.labour.org.nz/images/photobox_previous_on.gif";
		}		
	}
}

function toggleCountDisplay(){
	var photoCountDisplay = document.getElementById("photoCount");
	if(photoCountDisplay){
		photoCountDisplay.innerHTML = "Photo " + (photoIndex + 1) + " of " + photoArray.length;
	}
	return;
}

function ToggleCaption(){

	if(captionBox && captionArray[photoIndex]){
		captionBox.innerHTML = captionArray[photoIndex];
		photoView.title = captionArray[photoIndex];
	}else{
		captionBox.innerHTML = "";
	}
}