title: how to get empty row in DropDownList
body: <p>i have this citys in my database:</p>
  
  <pre><code>city1
  city2
  city3
  city4
  </code></pre>
  
  <p>i what to see this in my DropDownList:</p>
  
  <pre><code>[empty]
  city1
  city2
  city3
  city4
  </code></pre>
  
  <p>this is my bind code:</p>
  
  <pre><code>SQL = "select distinct City from MyTbl order by City";
  dsClass = new DataSet();
  adp = new SqlDataAdapter(SQL, Conn);
  adp.Fill(dsClass, "MyTbl");
  adp.Dispose();
  DropDownList3.DataSource = dsClass.Tables[0];
  DropDownList3.DataTextField = dsClass.Tables[0].Columns[0].ColumnName.ToString();
  DropDownList3.DataValueField = dsClass.Tables[0].Columns[0].ColumnName.ToString();
  DropDownList3.DataBind();
  </code></pre>
  
  <p>how to do it (asp.net C#) ?</p>
  
  <p>thanks in  advance</p>