/* library */
function $(element)
{
	if (typeof element == 'string')
	{
		return document.getElementById(element);
	}
	else
	{
		return element;
	}
}

/*  specific functions*/
document.onload = setTimeout("init()",50);
var currentPage = 0;
var pageCount = 0;
var pages;

function init()
{
	initPages();
	setPages();
	setPageButtons();
	initFlipImage("leftNav");
	initFlipImage("rightNav");
	initFlipImage("help");
}

function initPages()
{
	pages = $("text").getElementsByTagName("div");
	pageCount = pages.length;	
}

function setPages()
{	
	for(var i=0; i< pages.length; i++)
	{		
		pages[i].style.display = (i==currentPage)?"block":"none";
	}
}

function nextPage()
{
	if (currentPage+1 < pageCount)
	{
		currentPage ++;
        setPages();		
		setPageButtons();
	}
}

function prevPage()
{
	if (currentPage-1 >= 0)
	{
		currentPage --;
        setPages();	
		setPageButtons();		
	}
}

function setPageButtons()
{
	$("nextPage").style.display = (currentPage == pageCount-1)?"none":"block";
	$("prevPage").style.display = (currentPage == 0)?"none":"block";
}

function initFlipImage(container)
{
	var element = $(container);
	if(element)
	{
		var links = element.getElementsByTagName("a");
		for(var i=0; i< links.length; i++)
		{
			var images = links[i].getElementsByTagName("img");			
			if ( images.length > 0)
			{
				var src = images[0].src;				
				if (src.match(/_na\.gif/))
				{									
					images[0].onmouseover = flipImage;
					images[0].onmouseout = flipImage;
					images[0].onclick = resetImage;
				}
			}			
		}
	}
}

function flipImage()
{	
    var src = this.src;	
	if (src.match(/_na\.gif/))
	{
		src = src.replace(/_na\.gif/,"_on.gif");
	}
	else
	{
		src = src.replace(/_on\.gif/,"_na.gif");
	}
	this.src = src;
}

function resetImage()
{	
    var src = this.src;	
	if (src.match(/_on\.gif/))
	{
		src = src.replace(/_on\.gif/,"_on.gif");
	}	
	this.src = src;
}

function flipHelp()
{
	var element = $("help");
	if (element)
	{
		if (element.style.display == "block")
		{
			element.style.display ="none";
		}
		else
		{
			element.style.display ="block"
		}
	}
}