function tabdiv(obj,num,len,cn)
{
 var cssname=cn;
 for(var id = 1;id<=len;id++)
{ 
  var ss=obj+id;
  var snav =obj+"nav"+id;
  if(id==num){
  try{document.getElementById(ss).style.display="block"}catch(e){};
  try{document.getElementById(snav).className=cssname}catch(e){};
  }else{
  try{document.getElementById(ss).style.display="none"}catch(e){};
  try{document.getElementById(snav).className=""}catch(e){};
  }
 }  
}