title: RadioButtonList OnSelectedIndexChanged
body: <p>I'm looking for the best way to handle a change of index being selected on a ASP.net RadioButtonList (C# code behind).  I have 3 list items.  For the first one, I want it to show a hidden asp:textbox on the page, whereas the other 2 will hide the textbox.  </p>
  
  <pre><code>//asp.net side
  &lt;asp:RadioButtonList ID="_indicatorAckType" runat="server" RepeatDirection="Horizontal"
                  enabled="true" OnSelectedIndexChanged="onAckTypeChanged"&gt;
      &lt;asp:ListItem Text="None" /&gt;
      &lt;asp:ListItem Text="SHOW" /&gt;   
      &lt;asp:ListItem Text="HIDE" /&gt;
  &lt;/asp:RadioButtonList&gt;
  
  //code behind
  protected void onAckTypeChanged(object sender, EventArgs e)
  {
      if (_indicatorAckType.SelectedItem.Text == "SHOW")
          _myTextboxID.Visible = true;
      else
          _myTextboxID.Visible = false;
  }
  </code></pre>
  
  <p>I initially tried using onclick event handlers, but I've been told that ListItem's cannot use onclick events with radio button items. What am I doing wrong here?  This does not throw any errors or have any visibly obvious problems.  I have tried making onSelectedIndexChanged do nothing except show the textbox and that doesn't work either.  </p>
  
  <p>Any help is appreciated!  Thanks everyone.</p>