title: Set the value of an unbound DropDownList based on values passed in a querystring
body: <p>I'm trying to set the value of an unbound <code>DropDownList</code> based on values passed in a query string without success.</p>
  
  <p>I don't have error but in <code>DropDownList</code> the value passed in a query string is not selected.</p>
  
  <p>Here is my code.</p>
  
  <p><strong>In <code>page1.aspx</code></strong>:</p>
  
  <pre><code>Server.Transfer("page2.aspx?dt=" + myDateDDL.SelectedItem.ToString());
  </code></pre>
  
  <p><strong>In <code>page2.aspx</code></strong>:</p>
  
  <pre><code>Server.Transfer("page1.aspx?dt=" + Request.QueryString["dt"].ToString());
  </code></pre>
  
  <p><strong>In <code>page1.aspx</code></strong>:</p>
  
  <pre><code>protected void Page_Load(object sender, EventArgs e)
  {
      if (!Page.IsPostBack)
      {
         if (!String.IsNullOrWhiteSpace(Request.QueryString["dt"]))
         {
             myDateDDL.SelectedValue = Request.QueryString["dt"].ToString();
         }
      }
  }
  </code></pre>
  
  <p>Please help me.</p>
  
  <p>Thank you in advance.</p>