var u=1;
var d=7;
var t=13;
var q=19;

var imgdir="images/";

if (document.images) {
	var f1 = new Image(); f1.src = imgdir + "_a01.jpg";
	var f2 = new Image(); f2.src = imgdir + "_a02.jpg";
	var f3 = new Image(); f3.src = imgdir + "_a03.jpg";
	var f4 = new Image(); f4.src = imgdir + "_a04.jpg";
        var f5 = new Image(); f5.src = imgdir + "_a05.jpg";
        var f6 = new Image(); f6.src = imgdir + "_a06.jpg";
        var f7 = new Image(); f7.src = imgdir + "_b01.jpg";
        var f8 = new Image(); f8.src = imgdir + "_b02.jpg";
        var f9 = new Image(); f9.src = imgdir + "_b03.jpg";
        var f10 = new Image(); f10.src = imgdir + "_b04.jpg";
        var f11 = new Image(); f11.src = imgdir + "_b05.jpg";
        var f12 = new Image(); f12.src = imgdir + "_b06.jpg";
        var f13 = new Image(); f13.src = imgdir + "_c01.jpg";
        var f14 = new Image(); f14.src = imgdir + "_c02.jpg";
        var f15 = new Image(); f15.src = imgdir + "_c03.jpg";
        var f16 = new Image(); f16.src = imgdir + "_c04.jpg"; 
        var f17 = new Image(); f17.src = imgdir + "_c05.jpg"; 
        var f18 = new Image(); f18.src = imgdir + "_c06.jpg"; 
        var f19 = new Image(); f19.src = imgdir + "_d01.jpg"; 
        var f20 = new Image(); f20.src = imgdir + "_d02.jpg";
        var f21 = new Image(); f21.src = imgdir + "_d03.jpg";
        var f22 = new Image(); f22.src = imgdir + "_d04.jpg";
       var f23 = new Image(); f23.src = imgdir + "_d05.jpg";
       var f24 = new Image(); f24.src = imgdir + "_d06.jpg";
}

function change_im_1() {
	if (u<=6)
	{
	document.images["uno"].src = eval("f"+u+".src");
	u++;
	setTimeout("change_im_1()",2000); }	
	if (u>6) u=1;
}

function change_im_2() {
	if (d<=12)
	{
	document.images["due"].src = eval("f"+d+".src");
	d++;
	setTimeout("change_im_2()",2000); }	
	if (d>12) d=7;
}

function change_im_3() {
	if (t<=18)
	{
	document.images["tre"].src = eval("f"+t+".src");
	t++;
	setTimeout("change_im_3()",2000); }	
	if (t>18) t=13;
}

function change_im_4() {
	if (q<=24)
	{
	document.images["quattro"].src = eval("f"+q+".src");
	q++;
	setTimeout("change_im_4()",2000); }	
	if (q>24) q=19;
}

function init() {
	if (!document.images) return;
	setTimeout("change_im_1()",1000);
	setTimeout("change_im_2()",1500);	
	setTimeout("change_im_3()",2000);	
	setTimeout("change_im_4()",2500);	
}