function NotDisp(id_name){
  id=document.getElementById(id_name); 

  if(id.style.display=="block"){
    id.style.display="none";
  }
}

function dispChange(id_name) {
  id=document.getElementById(id_name); 
        
  if(id.style.display=="none"){
    id.style.display="block"; 
  } 
 }