function mostrar(num) {
	state = document.getElementById('r'+num).style.display;
	esconderTodos();
	state = (state == 'block') ? 'none' : 'block';
	document.getElementById('r'+num).style.display = state;
}

function esconderTodos() {
	var i = 1;
	var id = 'r' + i;
	var preg = document.getElementById(id);

	while (preg != null) {
		preg.style.display = 'none';
		i++;
		id = 'r' + i;
		preg = document.getElementById(id);
	}
}