function displayOrHide(_obj,_obj1,_obj2,_obj3){
 document.getElementById(_obj).style.display = "none";
 document.getElementById(_obj1).style.display = "none";
 document.getElementById(_obj2).style.display = "none";
 document.getElementById(_obj3).style.display = "block";
}

function clickEvent(obj){
    
 for(i=0;i<obj.parentNode.childNodes.length;i+=3){
    obj.parentNode.childNodes[i].className = "background";
  }
  obj.className = "background01";
 
}