// JavaScript Document
 function changeTab(index)
        {
            for (var i=1;i<=4;i++)
            {
                document.getElementById ("li_"+i).className ="normal";
                document.getElementById ("div1"+i).style.display  ="none";
            }
            
            document.getElementById ("li_"+index).className ="selected";
            document.getElementById ("div1"+index).style.display  ="block";
        }