protected void Button1_Click(object sender, EventArgs e)
    {
        string yonghuming = this.TextBox1.Text.Trim();
        string mima = this.TextBox2.Text.Trim();
        string str = "select count(*) from denglu where yonghuming='" + yonghuming + "'and mima='" + mima + "'";
        OleDbConnection con = new OleDbConnection(System.Configuration.ConfigurationManager.AppSettings["SQLConnString"].ToString());
        OleDbCommand com = new OleDbCommand(str, con);
        con.Open();
        int ret = com.ExecuteNonQuery();
        con.Close();
        if (ret > 1)
        {
            Response.Redirect("~/首页.aspx");
        }
        else
        {
            Response.Write("<script>alert('用户帐号/密码错误。')</script>");

        }