function toggle_visibility(id, label) {
   var e = document.getElementById(id);
   var e2 = document.getElementById(label);
   
   if(e.style.display == 'block'){
      e.style.display = 'none';
	  e2.innerHTML = 'show comment';
   }
   else{
      e.style.display = 'block';
 	  e2.innerHTML = 'hide comment';
   }
}