function index(i)
{ 
  for(j=1;j<6;j++)
    {
  if(i==j){
   document.getElementById("a"+j).className="li2";
   document.getElementById("b"+j).style.display="";
          }
   else
    {
   document.getElementById("a"+j).className="li1";
   document.getElementById("b"+j).style.display="none";
      }
     }
  
}
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