Greeting for all,

When I run the below code by VB 2013, it returns me back to

Code:
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
I don't know what is going on

CAN ANY BODY HELP ME TO SOLVE THAT ASAP?

Thanks in advance.

My Code is the following:

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

public partial class Default2 : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            DropDownList1.AppendDataBoundItems = true;
            string CS = "Provider=Microsoft.ACE.OleDb.12.0;Data Source=|DataDirectory|db1.mdb";
            OleDbConnection con = new OleDbConnection(CS);
            OleDbCommand cmd = new OleDbCommand("Select * from [tblCarMaker]", con);

            try
            { 
                con.Open();
                DropDownList1.DataSource=cmd.ExecuteReader();
                DropDownList1.DataTextField="Maker_Name";
                DropDownList1.DataValueField="Maker_ID";
                DropDownList1.DataBind();
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally{
                con.Close();
                con.Dispose();
            }
        }
        
    }
    protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        DropDownList2.Items.Clear();
        DropDownList2.Items.Add(new ListItem("--Select Car Model--", ""));
        DropDownList3.Items.Clear();
        DropDownList3.Items.Add(new ListItem("---Select Car Year--", ""));

        DropDownList2.AppendDataBoundItems = true;

        string CS = "Provider=Microsoft.ACE.OleDb.12.0;Data Source=|DataDirectory|db1.mdb";
        OleDbConnection con = new OleDbConnection(CS);
        String strQuery = "Select [CarMaker_ID], [Model_Name] , [tblCarMaker].[Maker_ID] from [tblCarModel], [tblCarMaker] where [tblCarMaker].[Maker_ID]=[tblCarModel].[CarMaker_ID];";
        OleDbCommand cmd = new OleDbCommand();
        cmd.Parameters.AddWithValue("CarMaker_ID", DropDownList1.SelectedItem.Value);
        cmd.CommandType= CommandType.Text;
        cmd.CommandText= strQuery;
        cmd.Connection= con;

        try
        { 
            con.Open();
            DropDownList2.DataSource=cmd.ExecuteReader();
            DropDownList2.DataTextField="Model_Name";
            DropDownList2.DataValueField="Model_ID";
            DropDownList2.DataBind();
            if (DropDownList2.Items.Count > 1)
            {
                DropDownList2.Enabled = true;
            }
            else
            {
                DropDownList2.Enabled = false;
                DropDownList3.Enabled = false;
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally{
            con.Close();
            con.Dispose();
        }

    }
    protected void DropDownList2_SelectedIndexChanged(object sender, EventArgs e)
    {
        DropDownList3.Items.Clear();
        DropDownList3.Items.Add(new ListItem("--Select Car Year", ""));
        DropDownList3.AppendDataBoundItems = true;

        string CS = "Provider=Microsoft.ACE.OleDb.12.0;Data Source=|DataDirectory|db1.mdb";
        OleDbConnection con = new OleDbConnection(CS);
        OleDbCommand cmd = new OleDbCommand("Select [Module_ID], [Car_Year] from [tblCarYear] Where [tblCarModul].[Model_ID]=[tblCarYear].[Modele_ID];", con);

        try
        {
            con.Open();
            DropDownList3.DataSource = cmd.ExecuteReader();
            DropDownList3.DataTextField = "Car_Year";
            DropDownList2.DataValueField = "ID";
            DropDownList2.DataBind();
            if (DropDownList3.Items.Count > 1)
            {
                DropDownList3.Enabled = true;
            }
            else
            {
                DropDownList2.Enabled = false;
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            con.Close();
            con.Dispose();
        }

    }
    protected void DropDownList3_SelectedIndexChanged(object sender, EventArgs e)
    {
        lblResults.Text = "You Selected" +
                        DropDownList1.SelectedItem.Text + "----->" +
                        DropDownList2.SelectedItem.Text + "----->" +
                        DropDownList3.SelectedItem.Text;
    }
}