Why the image is not displaying in the web page

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.OleDb;
using System.Data;


public partial class Retrive_Data_From_Database_and_display_in_TextBox : System.Web.UI.Page
{
    OleDbConnection con;
    OleDbCommand com;
    OleDbDataAdapter da;
    DataSet ds;
    protected void Page_Load(object sender, EventArgs e)
    {
        con = new System.Data.OleDb.OleDbConnection();
        ds = new DataSet();
        con.ConnectionString = "PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("~/kamnagroup.mdb") + "";
        string sql = "select aname,add1,photo,point from joining WHERE point=(SELECT MAX(point) FROM joining)";
        da = new System.Data.OleDb.OleDbDataAdapter(sql,con);
        con.Open();
        da.Fill(ds,"joining");
        navigatedata();
        con.Close();
        con.Dispose();
    }
    private void navigatedata()
    {
        DataRow dRow=ds.Tables["joining"].Rows[0];
        
        TextBox1.Text = dRow.ItemArray.GetValue(0).ToString();
        TextBox2.Text = dRow.ItemArray.GetValue(1).ToString();
        TextBox3.Text = dRow.ItemArray.GetValue(2).ToString();
        TextBox4.Text = dRow.ItemArray.GetValue(3).ToString();
        Image1.ImageUrl = TextBox3.Text;
        
    }
}