var cont = 1;
var tempo = 0;
function cases(num, tot){
	
	var bg = "url("+document.getElementById("img_"+num).src+")";
	document.getElementById("imgAtual").style.background = bg;
	var n = parseInt(tot);
	for(var i = 1; i <= n; i++){
		document.getElementById("img_"+i).style.border = "solid 2px #4c4c4c";
	}
	
	document.getElementById("img_"+num).style.border = "solid 2px #ff9933";
	
	if(num == tot){
		cont = "1";
	}else{
		cont = num + 1;
	}
	
	clearTimeout(tempo);	
	tempo = setTimeout("cases("+cont+", "+tot+")", 8000);
}