bootstrap下拉列表重置联动

/**添加&修改时--获取机柜号**/
    function BindSelectJgh(jiguiColumnIdD, jiguiNumberIdD) {
        var jid = !jiguiColumnIdD ? $('#jiguiColumnId').val() : jiguiColumnIdD;
        var jgh = $('#jiguiNumberId');

        jgh.find("option").remove();
        jgh.append("<option value=''>&nbsp;--请选择--</option>");
        jgh.val(null);
        jgh.trigger('change.select2');
        
        $.ajax({
            type : "post",
            url : '<c:url value="getJiguiJiguiNumber.do"/>',
            dataType : "json",
            data : {
                'jiguiNumber.jiguiColumn.id' : jid
            },
            success : function(data) {
                if (data.success == true) {
                    $.each(data.rows, function(i, item) {
                        jgh.append("<option value='" + item.id + "'>&nbsp;" + item.name + "</option>");
                    });

                    if (jiguiNumberIdD) {
                        jgh.val(jiguiNumberIdD);
                        jgh.trigger('change.select2');
                    }

                } else {
                    errorbox(data.msg);
                }
            }
        });
    }