text: $(document).ready(function () {
      $('.change_page').unbind('click').click(function(){
          clean_main_content_container(function(){console.log('listo!')}, 'programacion_ajax')
      });
  });
  
  function clean_main_content_container(callback, page_to_load){
      $('.main_content_container').empty();
      $('.main_content_container').load(page_to_load, function(){
          $('.j_home_intro').hide();
          callback();
      });
  }