function showTab(tabNum) {
  document.getElementById('label_1').className='';
  document.getElementById('label_2').className='';
  document.getElementById('tab_1').style.display='none';
  document.getElementById('tab_2').style.display='none';
  document.getElementById('tab_'+tabNum).style.display='block';
}
function showSaturday() {
  document.getElementById('label_saturday').className='active';
  document.getElementById('label_sunday').className='';
  document.getElementById('tab_saturday').style.display='block';
  document.getElementById('tab_sunday').style.display='none';
}
function showSunday() {
  document.getElementById('label_saturday').className='';
  document.getElementById('label_sunday').className='active';
  document.getElementById('tab_saturday').style.display='none';
  document.getElementById('tab_sunday').style.display='block';
}