tabArray = new Array();

function changeTab(what, tabArray){

      for(var i=0; i < tabs.length; i++ ){
              document.getElementById('a' + tabArray[i]).style.backgroundColor='#D2E1FE';
              document.getElementById(tabArray[i] + 'Div').style.display='none';
      }
      
      document.getElementById('a' + what).style.backgroundColor='white';
      document.getElementById(what + 'Div').style.display='block';

  }