function voltar(){
	history.go(-1)
}

function showElement(id) {
if(document.getElementById(id).style.display != 'block'){
		document.getElementById(id).style.display= 'block';
		document.getElementById(id).style.visibility = 'visible';
		document.getElementById(id).style.position = 'static';
	}else {
		document.getElementById(id).style.display= 'none';
		document.getElementById(id).style.visibility = 'hidden';
		document.getElementById(id).style.position = 'static';
	}
}