/************************************************************************************************************
	(C) www.dhtmlgoodies.com, November 2005
	with changes by Anikanov A.A., October 2007 
	************************************************************************************************************/

	var arrowImageHeight = 45;	// Height of arrow image in pixels;
	var slideSpeed = 0;
	var previewImageParent = false;
	var previewImagePane = false;
	var slideEndMarker = false;

	function getTopPos(inputObj)
	{		
	
	  var returnValue = inputObj.offsetTop;
	  while((inputObj = inputObj.offsetParent) != null)returnValue += inputObj.offsetTop;
	  return returnValue;
	}
	
	function initSlide(e)
	{
		if(document.all)e = event;
		
		slideSpeed = e.clientY + Math.max(document.body.scrollTop,document.documentElement.scrollTop) - getTopPos(this);

		if(this.getAttribute("id") == "next") { slideSpeed = (slideSpeed)*-1; }
		else { slideSpeed = arrowImageHeight - slideSpeed; }

		slideSpeed = Math.round(slideSpeed * 10 / arrowImageHeight);
	}
	
	function stopSlide() { slideSpeed = 0; }

	function slidePreviewPane()
	{
		if(slideSpeed!=0)
		{
			var topPos = previewImagePane.style.top.replace(/[^\-0-9]/g,'')/1;	
		
			if(slideSpeed<0 && slideEndMarker.offsetTop<(previewImageParent.offsetHeight - topPos)) { slideSpeed=0; }
			topPos = topPos + slideSpeed;
			if(topPos>0) topPos=0;

		 	previewImagePane.style.top = topPos + 'px';
	 	
		}
	 	setTimeout('slidePreviewPane()',30);		
	}
	
	function revealThumbnail()
	{
		this.style.filter = 'alpha(opacity=100)';
		this.style.opacity = 1;
	}
	
	function hideThumbnail()
	{
		this.style.filter = 'alpha(opacity=100)';
		this.style.opacity = 1.0;
	}

	function initGalleryScript()
	{
		previewImageParent = document.getElementById('ViewPort');
		previewImagePane = document.getElementById('SlideBar');
		previewImagePane.style.top = '0px';

		var images = previewImagePane.getElementsByTagName('IMG');
		for(var no=0;no<images.length;no++)
		{
			images[no].onmouseover = revealThumbnail;
			images[no].onmouseout = hideThumbnail;
		}	

		slideEndMarker = document.getElementById('slideEnd');

		var prev_button = document.getElementById('prev');
		var next_button = document.getElementById('next');
		prev_button.onmousemove = initSlide;
		next_button.onmousemove = initSlide;
		prev_button.onmouseout = stopSlide;
		next_button.onmouseout = stopSlide;
		
		slidePreviewPane();
	}

	window.onload = initGalleryScript;