// JavaScript Document

// <![CDATA[
var headerOK 		= false;
var path 			= "/images/headers/";
var headers 		= new Array('1.jpg', '2.jpg', '4.jpg', '3.jpg')
var preloadedImgs 	= new Array();
var interval 		= 7500;
var current  		= 0;
var tot_headers 	= (headers.length-1);
var imgsLoaded		= 0;

// timer ID
var checkTimer 	= false;
var imgTimer 	= false;

function nextImg() {
	next_num = (current < tot_headers) ? current + 1 : 0;
	complete_path = path + headers[next_num];
	
	var newImg 				= document.createElement("img");
	newImg.id 				= "headImg";
	newImg.src 				= complete_path;
	newImg.style.display 	= "none";
	new Effect.Fade('headImg', {duration: 0.5, afterFinish: function() {changeImg()}
	});
	function changeImg(){
		$('header').replaceChild(newImg, $('headImg'));
		Effect.Appear('headImg', { duration: 0.5 });
	}
	current = next_num;
}

function checkLoad(){

	if(imgsLoaded >= tot_headers){
		$('headImg').src = path + headers[0];
		if(!imgTimer && $('headImg')){
			clearInterval(checkTimer);
			imgTimer = setInterval("nextImg()", interval);

		}
	}
}
	
function startHeader() {
	// faccio il preload delle immagini
	for (i = 0; i < tot_headers; i++){
		complete_path 			= path + headers[i];
		preloadedImgs[i] 		= document.createElement("img");
		preloadedImgs[i].onload = function() {imgsLoaded++};
		preloadedImgs[i].src 	= complete_path;
		
	}
	checkTimer = setInterval("checkLoad()", 500);
}

// ]]>