使用$ .ajax到$ .post？

I have this code js :

$(document).on("click", "#nextMonth", function(e) 
{
   $.post(
     'ajax/genererCalendrier.php',
     {
       "mois":mois, "annee":annee
     },
     function(data)
     {
         data = jQuery.parseJSON(data);  
     }).success(function()
     {
       $('#divCalendrier').html(calendrier);
       $.ajax(
       {
         url: 'ajax/genererCalendrier.php',
         type: 'POST',
         data:
         {
           'action':'rafraichir_nombre_jours_conges' 
         },
         dataType:'text',
         success: function(retour_php)
         {
           alert(retour_php);
         },
         error: function()
         {
          alert("pas ok");
         }
       });
     }).error(function()
     {
        $('#divCalendrier').html('<p class="error">Erreur lors de la requête AJAX</p>');
     });
});

This alert does not launch :

alert(retour_php);

Is my code ($.ajax into $.post) is correct ?

I have no error with firebug.

I can't understand your javascript's logic. If you are using this syntax:

$.post(
  'ajax/genererCalendrier.php',
  {
    "mois":mois, "annee":annee
  },
  function(data)
  {
      data = jQuery.parseJSON(data);  
  })

You are already have success handler, and and success event doesn't fire at all! I suggest you addalert` message in function, like this:

$.post(
  'ajax/genererCalendrier.php',
  {
    "mois":mois, "annee":annee
  },
  function(data)
  {
      data = jQuery.parseJSON(data);
      alert(data);
  })

I'm sure you'll got the message and everything will work. So your code should be something like:

$.post(
  'ajax/genererCalendrier.php',
  {
    "mois":mois, "annee":annee
  },
  function(data)
  {
     data = jQuery.parseJSON(data);
     $('#divCalendrier').html(calendrier);
     $.ajax(
     {
       url: 'ajax/genererCalendrier.php',
       type: 'POST',
       data:
       {
         'action':'rafraichir_nombre_jours_conges' 
       },
       dataType:'text',
       success: function(retour_php)
       {
         alert(retour_php);
       },
       error: function()
       {
        alert("pas ok");
       }
     });
  },
  error:function()
  {
     $('#divCalendrier').html('<p class="error">Erreur lors de la requête AJAX</p>');
  })

Complete $.post documentation