function trocaAbba(n) {
    if(n == 0) {
       document.getElementById('previsao').style.display = 'block';
       document.getElementById('agora').style.display = 'none';
	document.getElementById('abba_02').style.background = '#d7d5b2';
	document.getElementById('abba_02').style.top = '11px';	
	document.getElementById('abba_01').style.background = '#fffee7';
	document.getElementById('abba_01').style.top = '12px';
    } else if (n == 1) {
       document.getElementById('previsao').style.display = 'none';
       document.getElementById('agora').style.display = 'block';
	document.getElementById('abba_02').style.background = '#fffee7';
	document.getElementById('abba_02').style.top = '12px';
	document.getElementById('abba_01').style.background = '#d7d5b2';	
	document.getElementById('abba_01').style.top = '11px';
   }
}