[Web] หน้า Edit Form Error ตรง hplEdit.NavigateUrl อ่ะค่ะ เขียนตามในเว็บนะแต่มัน Error ค่ะ

DataBinder.Eval(e.Row.DataItem, "Used").ToString();

<script runat="server">
	MySqlConnection objConn = new MySqlConnection();
	MySqlCommand objCmd = new MySqlCommand();
	MySqlDataReader dtReader;
	String strConnString,strSQL;

    void Page_Load(object sender,EventArgs e)
	{
        strConnString = "Server=localhost;User Id=root; Password=root; Database=otanisite; Pooling=false";
		objConn = new MySqlConnection(strConnString);
		objConn.Open();

		if(!Page.IsPostBack)
		{
			ViewData();
		}
    }

	void ViewData()
	{
		//*** DataTable ***//
		MySqlDataAdapter dtAdapter;
		DataTable dt = new DataTable();
        strSQL = "SELECT * FROM t_product WHERE TireID = '" + Request.QueryString["TireID"] + "' ";
		dtAdapter = new MySqlDataAdapter(strSQL, objConn);
		dtAdapter.Fill(dt);

		if(dt.Rows.Count > 0)
		{
            this.txtTireSizes.Text = (string)dt.Rows[0]["TireSizes"];
            this.ddlPattern.Text = (string)dt.Rows[0]["PatternID"].ToString();
            this.txtPly.Text = (string)dt.Rows[0]["Ply"].ToString();
            this.txtType.Text = (string)dt.Rows[0]["Type"];
            this.txtMaxSpeed.Text = (string)dt.Rows[0]["MaxSpeed"].ToString();
            this.txtRim.Text = (string)dt.Rows[0]["Rim"].ToString();
            this.txtInfPsi.Text = (string)dt.Rows[0]["InfPsi"].ToString();
            this.txtInfKgf.Text = (string)dt.Rows[0]["InfKgf"].ToString();
            this.txtLoadLimits.Text = (string)dt.Rows[0]["LoadLimits"].ToString();
            this.txtSectionWidth.Text = (string)dt.Rows[0]["SectionWidth"].ToString();
            this.txtOverDiameter.Text = (string)dt.Rows[0]["OverDiameter"].ToString();
            this.txtSkidDep.Text = (string)dt.Rows[0]["SkidDep"].ToString();
		}
	}
    
    void btnSave_Click(Object sender, EventArgs e)        			
	{
        strSQL = "UPDATE t_product SET " +
        " TireSizes = '" + this.txtTireSizes.Text + "' " +
        " ,PatternID = '" + this.ddlPattern.Text + "' " +
        " ,Ply = '" + this.txtPly.Text + "' " +
        " ,Type = '" + this.txtType.Text + "' " +
        " ,MaxSpeed = '" + this.txtMaxSpeed.Text + "' " +
        " ,Rim = '" + this.txtRim.Text + "' " +
        " InfPsi = '" + this.txtInfPsi.Text + "' " +
        " ,InfKgf = '" + this.txtInfKgf.Text + "' " +
        " ,LoadLimits = '" + this.txtLoadLimits.Text + "' " +
        " ,SectionWidth = '" + this.txtSectionWidth.Text + "' " +
        " ,OverDiameter = '" + this.txtOverDiameter.Text + "' " +
        " ,SkidDep = '" + this.txtSkidDep.Text + "' " +
        " WHERE TireID = '" + Request.QueryString["TireID"] + "' ";

        objCmd = new MySqlCommand();
        objCmd.Connection = objConn;
        objCmd.CommandText = strSQL;
        objCmd.CommandType = CommandType.Text;		
						
		this.pnlAdd.Visible = false;
		try
		{
			objCmd.ExecuteNonQuery();
			this.lblStatus.Text = ".::Record Updated::.";
			this.lblStatus.Visible = true;
            this.btnBack.Visible = true;
		}
		catch (Exception ex)
		{
			this.lblStatus.Text = "Record can not update";
		}

    }

	void Page_UnLoad()
	{
		objConn.Close();
		objConn = null;
	}

</script>