function makeSublist(parent, child, isSubselectOptional, childVal) {
      $("body").append("<select style='display:none' id='" + parent + child + "'></select>");
      $('#' + parent + child).html($("#" + child + " option"));

      var parentValue = $('#' + parent).attr('value');
      $('#' + child).html($("#" + parent + child + " .sub_" + parentValue).clone());

      childVal = (typeof childVal == "undefined") ? "" : childVal;
      $("#" + child + ' option[@value="' + childVal + '"]').attr('selected', 'selected');

      $('#' + parent).change( function() {
		    var parentValue = $('#' + parent).attr('value');
		    $('#' + child).html($("#" + parent + child + " .sub_" + parentValue).clone());
		    if (isSubselectOptional) $('#' + child).prepend("<option value='none' selected> 選択してください </option>");
		      $('#' + child).trigger("change");
		    $('#' + child).focus();
		    });
    }

    $(function() {

      makeSublist('child', 'grandsun', true, '');
      makeSublist('parent', 'child', false, '1');

    });