function FileImageSequence()
{
}

FileImageSequence.getCurrentIndex = function()
{
	var current = document.getElementById("docImage").src;
	var ret = -1;
	//find the index of the current in the image array
	for (var i = 0; i < docImages.length; ++i)
	{
		if (current.indexOf(docImages[i]) != -1)
		{
			ret = i;
			break;
		}
	}
	return ret;
}

FileImageSequence.onclick_prev = function(evt)
{
	if (typeof(evt.target) == "undefined")
	{
		evt.target = evt.srcElement;
	}
	
   	evt.target.blur();

	var currentIndex = FileImageSequence.getCurrentIndex();
	
	if (currentIndex > 0)
	{
		currentIndex = currentIndex - 1;
		document.getElementById("docImage").src       = docImages[currentIndex];
		document.getElementById("citation").innerHTML = citations[currentIndex];
	}
	
	FileImageSequence.mediator();
};

FileImageSequence.onclick_next = function(evt)
{
	if (typeof(evt.target) == "undefined")
	{
		evt.target = evt.srcElement;
	}
	
   	evt.target.blur();
	
	var currentIndex = FileImageSequence.getCurrentIndex();
	var maxIndex = docImages.length - 1;
	
	if (currentIndex < maxIndex)
	{
		currentIndex = currentIndex + 1;
		document.getElementById("docImage").src = docImages[currentIndex];
		document.getElementById("citation").innerHTML = citations[currentIndex];
	}
	
	FileImageSequence.mediator();
};

FileImageSequence.mediator = function()
{
	var currentIndex = FileImageSequence.getCurrentIndex();
	var maxIndex = docImages.length - 1;
	var minIndex = 0;
	
	document.getElementById("nextImage").disabled = (currentIndex == maxIndex);
	document.getElementById("prevImage").disabled = (currentIndex == minIndex);
	document.getElementById("imgCount").innerHTML = currentIndex + 1;
	document.getElementById("total").innerHTML    = maxIndex + 1;
};