var imageNames = new Array("01", "02", "03");
var arrImages = new Array();
var IMGS_PATH = "images/";
var currentIdx = 0;
var LAST_IDX = 3;
var mytimer = 0;
var slideshow = false;
var imgId =  "blendImg";
var	divId =  "blenddiv";

function preloadImages() { 
	
	var img = null; 
	for(var i = 0; i < LAST_IDX ; i++) { 
		img = new Image(); 
		img.src = IMGS_PATH + imageNames[i] + ".jpg"; 
		arrImages[i] = img; 
		
		
	} 
}


function getFormatedIDX(idx) { 
	return (idx < 10)? "0" + idx.toString(): idx.toString(); 
} 

function turnOn() { 
	if (mytimer != 0) window.clearTimeout(mytimer);
	blendimage(divId, imgId, arrImages[currentIdx].src, 200);
}



function startSlideshow() {
	if (!slideshow) {
		slideshow = true;
		mytimer = window.setTimeout("roll()", 5000);
		
	} else {
		slideshow = false;
		
		
	}
	
}	

function roll() {
	if (!slideshow) return;
	currentIdx++;
	
	setCurrentIdx();

	turnOn();
	
	
	mytimer = window.setTimeout("roll()", 5000);
}


function setCurrentIdx() {
	if (currentIdx == LAST_IDX)
		currentIdx = 0;
	else if (currentIdx == -1)
		currentIdx = LAST_IDX - 1;
}