title: Dropdownlist showing data for empty table
body: <p>I have a dropdownlist code like</p>
  
  <pre><code>protected void Page_Load(object sender, EventArgs e)
  {
      if (!IsPostBack)
      {
          fill1();
          fill();
          fill2();
      }
  }
  
  protected void fill1()
  {
      string str = "select distinct CompanyName from Company";
      SqlDataReader dr1 = conn.query(str);
      dwn.dropdwnlist(str, ddcompany);
  
  }
  
  protected void fill()
  {
      string company = ddcompany.SelectedValue.ToString();
      string str = "select CompanyID from Company where CompanyName='" + company + "'";
      SqlDataReader dr1 = conn.query(str);
      if (dr1.Read())
      {
          string id = dr1[0].ToString();
  
          string str1 = "select distinct Zone from Zone where CompanyID='" + id + "'";
          SqlDataReader dr = conn.query(str1);
          dwn.dropdwnlist(str1, ddzone);
      }
  
  }
  protected void fill2()
  {
      string zone = ddzone.SelectedValue.ToString();
      string str = "select ZoneID  from Zone where Zone='" + zone + "'";
      SqlDataReader dr1 = conn.query(str);
      if (dr1.Read())
      {
          string id = dr1[0].ToString();
          string str1 = "select distinct  Region from Region where ZoneID='" + id + "'";
          SqlDataReader dr = conn.query(str1);
          dwn.dropdwnlist(str1, ddregion);
      }
  
  }
  </code></pre>
  
  <p>I have two company named Infosys and wipro, and both companies have North,south and west zone respectively.In north and south zone i have some values but My west zone for both companies are empty but when i select west zone after selection south, the south zone values getting under west zone.North and south zone have same value with different id but when i select zone for both companies it not showing values by id .</p>