DataConn conn = new DataConn();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            CheckDay();
        }
    }
    public void WebMessageBox(string values)
    {
        string javaScript = @" <script  language  =  javascript> alert('" + values + "'); </script> ";
        ClientScript.RegisterStartupScript(this.GetType(), "javaScript", javaScript); 
        //this.Response.Write("<script>alert('"+values+"')</script>");
    }
    public void CheckDay()
    {
        SqlDataAdapter da = new SqlDataAdapter("select C_name,C_job,C_birthday from Client where C_type='超级客户' and (select datediff(day,C_birthday,getdate()))<5",conn.GetConnection());
        DataTable dt = new DataTable();
        da.Fill(dt);
        if(dt.Rows.Count>0)
        {
            string Tishi = "";
            for (int i = 0; i < dt.Rows.Count;i++ )
            {
                string xinxi = dt.Rows[i][0].ToString() + dt.Rows[i][1].ToString() + "的生日快要到了哦，日期是" + dt.Rows[i][2].ToString().Replace("0:00:00", "")+"\n";
                Tishi=Tishi+xinxi;
                TextBox1.Text = Tishi;
                WebMessageBox(xinxi);
            }
        }
    }