function hide_div_mess(id) {  
  var arr = document.getElementsByClassName('div_mess'); 
  for(var i = 0; i < arr.length; i++) { 
    arr[i].style.display = 'none';
  } 
  document.getElementById("id" + id).style.display = 'block'; 
}  
function hide_div_much(id) { 
  var arr = document.getElementsByClassName('div_much'); 
  for(var i = 0; i < arr.length; i++) { 
    arr[i].style.display = 'none';
  } 
  document.getElementById("id" + id).style.display = 'block'; 
}
function hide_div_npart(id) { 
  var arr = document.getElementsByClassName('div_npart'); 
  for(var i = 0; i < arr.length; i++) { 
    arr[i].style.display = 'none';
  } 
  document.getElementById("id" + id).style.display = 'block'; 
}