function changeTabMac(evt){
    tabdm = document.getElementById('tab-dicas-mac');
    tabrm = document.getElementById('tab-reviews-mac');
    contentdm = document.getElementById('dicas-mac');
    contentrm = document.getElementById('reviews-mac');
    if (evt == 'tab-dicas-mac'){
      tabdm.className = 'ativo';
      tabrm.className = '';
      contentdm.style.display = 'block';
      contentrm.style.display = 'none';
    }
    else{
      tabdm.className = '';
      tabrm.className = 'ativo';
      contentdm.style.display = 'none';
      contentrm.style.display = 'block';
    }
}
function changeTabIpod(evt){
    tabdi = document.getElementById('tab-dicas-ipod');
    tabri = document.getElementById('tab-reviews-ipod');
    contentdi = document.getElementById('dicas-ipod');
    contentri = document.getElementById('reviews-ipod');
    if (evt == 'tab-dicas-ipod'){
      tabdi.className = 'ativo';
      tabri.className = '';
      contentdi.style.display = 'block';
      contentri.style.display = 'none';
    }
    else{
      tabdi.className = '';
      tabri.className = 'ativo';
      contentdi.style.display = 'none';
      contentri.style.display = 'block';
    }
}
function changeTabIphone(evt){
    tabdp = document.getElementById('tab-dicas-iphone');
    tabrp = document.getElementById('tab-reviews-iphone');
    contentdp = document.getElementById('dicas-iphone');
    contentrp = document.getElementById('reviews-iphone');
    if (evt == 'tab-dicas-iphone'){
      tabdp.className = 'ativo';
      tabrp.className = '';
      contentdp.style.display = 'block';
      contentrp.style.display = 'none';
    }
    else{
      tabdp.className = '';
      tabrp.className = 'ativo';
      contentdp.style.display = 'none';
      contentrp.style.display = 'block';
    }
}