function isMemberOfCssClass(classes, thisClass)
{
	if(!classes)
	{
		return false;
	}
	var classArray = classes.split(" ");
	for(var i=0; i<classArray.length; ++i)
	{
		if(classArray[i] == thisClass)
		{
			return true;
		}
	}
	return false;
}


function addToCssClass(element, thisClass)
{
	element.className += ' ' + thisClass;
}

function removeFromCssClass(element, thisClass)
{
	var oldElementClass = element.className;
	var newClass = oldElementClass.replace(thisClass, "");
	element.className = newClass;
}




function showImage(element, targetID)
{
	imageSource = element.getElementsByTagName('img')[0].src;
	alt = element.getElementsByTagName('img')[0].alt;
	
	document.getElementById(targetID).src = imageSource;
	document.getElementById(targetID).alt = alt;
	
	return false;
}


function showThumbnailPage(element, targetID)
{

	var pageNumber = 0;

	var linkContainer = element.parentNode;
	var pageLinks = linkContainer.getElementsByTagName('a');
	for(var j=0; j < pageLinks.length; ++j)
	{
		if(isMemberOfCssClass(pageLinks[j].className, "selected") )
		{
			removeFromCssClass(pageLinks[j], "selected");
		}

		if(pageLinks[j] === element)
		{
			pageNumber = j;
			addToCssClass(pageLinks[j], "selected");
		}
	}


	var thumbnailPages = document.getElementById(targetID).getElementsByTagName('div');
	for(var i=0; i< thumbnailPages.length; ++i)
	{
		if(!isMemberOfCssClass(thumbnailPages[i].className, 'invisible'))
		{
			addToCssClass(thumbnailPages[i], 'invisible');
		}

		if(i == pageNumber)
		{
			removeFromCssClass(thumbnailPages[i], 'invisible');
		}
	}
	return false;
}