诡异的提交

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;public partial class news_news_view : System.Web.UI.Page
{
    SQLHelper sqlhelper = new SQLHelper();
    DataSet dtnews = new DataSet();
    DataSet dtreview = new DataSet();
    protected void Page_Load(object sender, EventArgs e)    {      
            if (Request["id"] != null)
            {
                if (!IsPostBack)
                {
                
                Binddata();
                
            }
            }
            else
            {
                Response.Redirect("news_list.aspx");
            }
       
    }
    public void Binddata()
    {
        sqlhelper.RunSQL("select * from Review where newsid='" + Request["id"] + "'", ref dtreview);
        DataList1.DataSource = dtreview.Tables[0];
        DataList1.DataKeyField = "reviewid";
        DataList1.DataBind();
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
红色部分为向表Review中插入数据
        SqlParameter[] prams ={
                sqlhelper.CreateInParam("@reviewname",SqlDbType.NVarChar,50,reviewname.Text),
                sqlhelper.CreateInParam("@reviewcontent",SqlDbType.NVarChar,100,reviewcontent.Text),
                sqlhelper.CreateInParam("@reviewtime",SqlDbType.NVarChar,50,System.DateTime.Now.ToString()),
                sqlhelper.CreateInParam("@newsid",SqlDbType.Int,50,Request["id"]),
                sqlhelper.CreateInParam("@newstitle",SqlDbType.NVarChar,50,newstitle.Text)
         };
        sqlhelper.RunProc("ReviewInsert", prams);
        Page.ClientScript.RegisterStartupScript(GetType(), "MyScript", "<script>alert('评论成功！');</script>");
        Panel1.Visible = false;
        Binddata();
           }
    protected void Button3_Click(object sender, EventArgs e)
    {
        Panel1.Visible = true;
        SetFocus(Button1);
    }
    protected void Button2_Click(object sender, EventArgs e)
    {
        Panel1.Visible = false;
    }
}存储过程：ALTER proc [dbo].[ReviewInsert]
@reviewname nvarchar(50),
@reviewcontent nvarchar(100),
@reviewtime nvarchar(50),
@newsid int,
@newstitle nvarchar(50)as
INSERT INTO [Manager].[dbo].[Review]
           ([reviewname]
           ,[reviewcontent]
           ,[reviewtime]
           ,[newsid]
,[newstitle])
     VALUES
           (
@reviewname
           ,@reviewcontent
           ,@reviewtime
           ,@newsid
,@newstitle)第一次向表中插入数据（即执行Button1）时成功，第二次向表中插入数据时失败，第三次成功，每隔一次失败一次有会的帮我看看，谢谢！！