var currentPos = 0;

function MoveLeft()
{
	if(currentPos > 0)
	{
		var listItems = GetListItems();
		
		currentPos--;
		listItems[currentPos].style.display = 'inline';
		listItems[currentPos + imgLength].style.display = 'none';
		
		SetActiveBtn((currentPos != 0),true);
	}	
}

function MoveRight()
{
	var listItems = GetListItems();
	
	if(listItems.length > currentPos + imgLength)
	{
		listItems[currentPos].style.display = 'none';
		listItems[currentPos + imgLength].style.display = 'inline';
		currentPos++;
		
		SetActiveBtn(true,((currentPos + imgLength) < listItems.length));
	}	
}

function GetImages()
{
	var divThumbnails = document.getElementById('thumbnails');
	var images = divThumbnails.getElementsByTagName('img');
	
	return images;
}

function GetListItems()
{
	var divThumbnails = document.getElementById('thumbnails');
	var listItems = divThumbnails.getElementsByTagName('li');
	
	return listItems;
}

function GetContainerDivs()
{
	var divThumbnails = document.getElementById('thumbnails');
	var divItems = divThumbnails.getElementsByTagName('div');
	
	return divItems;
}


function SetActiveBtn(isLeftBtnActive,isRightBtnActive)
{
	var imgArrowLeft = document.getElementById('thumbnailArrowLeft');
	var imgArrowRight = document.getElementById('thumbnailArrowRight');
	
	if(isLeftBtnActive)
	{
		imgArrowLeft.style.display = '';
	}
	else
	{
		imgArrowLeft.style.display = 'none';
	}
	
	if(isRightBtnActive)
	{
		imgArrowRight.style.display = '';
	}
	else
	{
		imgArrowRight.style.display = 'none';
	}
}

var activeImgThumb;
function ChangeMainImage(imgThumb)
{
	var imgMain = document.getElementById('productImageLarge');
	var indexOfLastSlash = imgThumb.src.lastIndexOf('/');
	var strLastSrc = imgThumb.src.substring(indexOfLastSlash);
	var imgSrc = imgThumb.src.replace('/1'+strLastSrc,'/3'+strLastSrc);
	
	imgMain.src = imgSrc;
	
	var anchorImg = GetParentByTag(imgMain,'A');
	
	if(anchorImg && anchorImg.tagName != 'BODY')
	{
		imgMain.parentNode.href=imgSrc;
	}
	
	if(activeImgThumb != null)
	{
		activeImgThumb.className = 'thumb';
	}
	else
	{
		var divItems = GetContainerDivs();
		
		for(i=0;i < divItems.length;i++)
		{
			divItems[i].className = 'thumb';
		}	
	}
	
	var activeDiv = GetParentByTag(imgThumb,'DIV');
	
	if(activeDiv && activeDiv.tagName != 'BODY')
	{
		activeDiv.className = 'thumb active';
	
		activeImgThumb = activeDiv;
	}
}

function GetParentByTag(currentElement, tagName)
{

	while(currentElement.tagName != tagName && currentElement.tagName != 'BODY')
	{
		currentElement = currentElement.parentNode;
	}
	
	if(currentElement.tagName != 'BODY')
	{
		return currentElement;
	}
	
	return null;
}