$(function() {
      // 規格1選択時
      $('select[name=classcategory_id1]')
          .change(function() {
                      var $form = $(this).parents('form');
                      var product_id = $form.find('input[name=product_id]').val();
                      var $sele1 = $(this);
                      var $sele2 = $form.find('select[name=classcategory_id2]');
                      setClassCategories($form, product_id, $sele1, $sele2);
                  });

      // 規格2選択時
      $('select[name=classcategory_id2]')
          .change(function() {
                      var $form = $(this).parents('form');
                      var product_id = $form.find('input[name=product_id]').val();
                      var $sele1 = $form.find('select[name=classcategory_id1]');
                      var $sele2 = $(this);
                      checkStock($form, product_id, $sele1.val(), $sele2.val());
                  });
});