function aparece_flash(posicao){
	var num=4;
	for(i=0;i<num;i++){
		if(i== posicao){
			document.getElementById('principal_'+i).style.display='';
			fadeIn('principal_'+i, 0.1);
			}else{
				document.getElementById('principal_'+i).style.display='none';
				}
		}
}
//#####################################################################################################################
function fadeIn(id, time) {
	target = document.getElementById(id);
	alpha = 0;
	timer = (time*1000)/50;
	var i = setInterval(
			function() {
				if (alpha >= 100)
					clearInterval(i);
				setAlpha(target, alpha);
				alpha += 2;
			}, timer);
}

function setAlpha(target, alpha) {
	target.style.filter = "alpha(opacity="+ alpha +")";
	target.style.opacity = alpha/100;
}