Code Before Response.Redirect doesn't Execute ?

Question

Hai Friends,
     
          I have prob in before Response.Redirect while executing the code.  
When i'm clicking button event, the below code has been executed. But The code before "Response.Redirect" doesn't execute, It just redirect the page. 


Code: -
         Application.Lock();

        DataTable dt3 = new DataTable();

        dt3 = (DataTable) Application["Online_User_List"];

        string sCond = string.Format("Count_No = '" + Session["Count_No"].ToString() + "'"); 

        DataRow[] drArray = dt3.Select(sCond);

        foreach (DataRow dr in drArray)

        {                                                                      

            dt3.Rows.Remove(dr);

            dt3.AcceptChanges();

        }

        Application["Online_User_List"] = dt3;

        Application["ImpactUsers"] = (int)Application["ImpactUsers"] - 1;

        //Page.ClientScript.RegisterStartupScript(this.GetType(), "MessageThenRedirect", "alert('" + Session["Count_No"].ToString() + "');", true);

       // DB.ExeAUD("delete  from betasys.temp_tb_session_mst t where t.s_no = '" + Session["Count_No"].ToString() + "'");

        Application.UnLock();

        Session.Abandon();

        Session.Clear();

        System.Threading.Thread.Sleep(3000);

        Response.Redirect("Login.aspx");

Thanks in Advance