// config variables -- intended to be changed by user.
// the interval at which images are switched in seconds
var secondsInterval = 3;

// the ID attribute of the image we'll be switching
var switchImageIdName = "web";

// program variables, not intended to be changed.
var timerId;
var imageCounter = 0;


function startSwitchTimer() {
	timerId = self.setTimeout("switchImage()", secondsInterval * 1000)
	preloadSwitchImages();
}

function preloadSwitchImages() {
	for(var i=0;i<switchImages.length;i++) {
	 	var preloadImage = new Image();
	 	preloadImage.src=switchImages[i];
	
	}

}

function switchImage() {
	imageCounter++;
	// go back to first image if imageCounter exceeds the amount of images
	if(imageCounter >= switchImages.length) {
		imageCounter = 0;
	}
	var img = document.getElementById(switchImageIdName);
	img.src = switchImages[imageCounter];
	timerId = self.setTimeout("switchImage()", secondsInterval * 1000)
}