这段代码有点问题，求大神指导。。。。实现的功能是：如果用户已登录，评价内容不为空，则提示评价成功！！！，评价内容为空，则提示操作失败，请重新操作！！！；如果用户未登录，则提示请先登录！！！。

namespace LBSYS.WebPage
{
    public partial class Comment : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void Button1_Click(object sender, EventArgs e)
        {

            LBSYS.Model.Message mes = new LBSYS.Model.Message();

            if (this.Request.Cookies["userid"].Value != "" && this.Request.Cookies["userid"].Value != null)
            {
                mes.Jingdian_Id = int.Parse(this.Request.QueryString["id"]);
                mes.Message_Content = this.TextBox3.Text;
                = DateTime.Now;
                try
                {
                    try
                    {
                        if (LBSYS.BLL.Message.Add(mes) > 0)
                        {
                            this.Response.Write("<script>alert('评论成功！！！');window.location='index.aspx'</script>");
                        }
                    }
                    catch (Exception)
                    {

                            this.Response.Write("<script>alert('操作失败，请重新操作！！！')</script>");
                    }
                }
                catch (Exception)
                {

                            this.Response.Write("<script>alert('请注意格式填写是否正确！！！')</script>");
                }  
            }
            else
            {

                           this.Response.Write("<script>alert('请先登录！！！');window.location='User_Login.aspx'</script>");
            }

        }