var randomnumber = Math.floor(Math.random()*slidecount);
var currentnumber = 0;
document.getElementById('slide'+currentnumber).style.display='block';
document.getElementById('control'+currentnumber).className='on';

var timebetweentransitions = 5; // seconds
var transitionlength = .3; // seconds
var opacitystepsize = 4; // evenly divisible by 100 (percentage of opacity)

var fadeinterval = transitionlength*opacitystepsize*10;
function imagerotate() {rotateInterval = setInterval('changeImage()',timebetweentransitions*1000);}
function changeImage() {
	if (currentnumber < slidecount-1) {newnumber = currentnumber+1} else {newnumber = 0;}
	changeImageTimeout = setTimeout('fadein(0)',0);
}

function fadein(currentopacity) {
	whichslide = 'slide'+newnumber;
	document.getElementById(whichslide).style.zIndex='5';
	document.getElementById(whichslide).style.display='block';
	document.getElementById('control'+currentnumber).className='';
	document.getElementById('control'+newnumber).className='on';
	if (currentopacity < 100) {
		newopacity = currentopacity+opacitystepsize;
		document.getElementById(whichslide).style.filter='alpha(opacity='+newopacity+')';
		document.getElementById(whichslide).style.MozOpacity=newopacity/100;
		document.getElementById(whichslide).style.opacity=newopacity/100;
		fadeinTimeout = setTimeout('fadein(newopacity)',fadeinterval);
	} else {
		document.getElementById('slide'+currentnumber).style.display='none';
		document.getElementById('slide'+newnumber).style.zIndex='1';
		currentnumber = newnumber;
		clearTimeout(fadeinTimeout);
	}
}

function stopslideshow(andgoto) {
	if (andgoto != currentnumber) {
		clearInterval(rotateInterval);
		newnumber = andgoto;
		fadeinTimeout = setTimeout('fadein(0)',0);
	}
}

imagerotate();