var slideSelected = 0;
var slideLength = 5;
var slideTimer;

function slideAutoStart()
{
	if (slideTimer)
		slideAutoStop();	
	else
		slideTimer = setInterval("slideShowNext()", 4500);
}

function slideAutoStop()
{
	slideTimer = clearInterval(slideTimer);
}

function slideShowPrev()
{
	if (slideSelected === false)
		slideShow(0);
	else if (slideSelected == 0)
		slideShow(slideLength - 1);
	else
		slideShow(slideSelected - 1);
}

function slideShowNext()
{
	if (slideSelected === false)
		slideShow(0);
	else if (slideSelected == (slideLength - 1))
		slideShow(0);
	else
		slideShow(parseInt(slideSelected) + 1);
}

function slideShow(i)
{
	if (i == slideSelected)
		return;
	var elem = document.getElementById("slide_"+i);
	if (elem)
	{	
		slideFadeIn(i);
		elem.className = elem.className.replace(/hidden/i, "visible");
	}
}

function slideHide(i)
{
	var elem = document.getElementById("slide_"+i);
	if (elem)
	{	
		elem.className = elem.className.replace(/visible/i, "hidden");
	}
}

function slideFadeIn(i)
{
	var elem = document.getElementById("slide_"+i);
	if (elem)
	{
		opacity_match = elem.className.match(/opacity([^\s]+)/i);

		if (!opacity_match)
		{
		elem.className = elem.className + " opacity20";
		}
	else
	{
		opacity_class = opacity_match[0];
		opacity = parseInt(opacity_match[1]);
		if (opacity == 100)
		{
			elem.className = elem.className.replace(opacity_class, "");
			if (slideSelected)
	 		{
	 			slideHide(slideSelected);
	 		}
	 		slideSelected = i;
			return;
		}

		opacity = opacity + 20;
		elem.className = elem.className.replace(opacity_class, "opacity"+opacity);
	}
	setTimeout("slideFadeIn("+i+")", 50);
	}			 	
}