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