var tabList = new Array();
var i=0;
function changeTab(tabname){
   for(j=0;j < tabList.length ; j++){
      document.getElementById(tabList[j]).style.display='none';
      document.getElementById('header'+tabList[j]).className='';
   }
   document.getElementById(tabname).style.display='';
   document.getElementById('header'+tabname).className='active';
}