title: asp.net checkbox event not firing
body: <p>I have a checkbox on a form:</p>
  
  <pre><code>&lt;asp:CheckBox ID="CheckBox1" runat="server"
  Visible="true" AutoPostBack="True" oncheckedchanged="CheckBox1_CheckedChanged" /&gt;
  </code></pre>
  
  <p>It is not firing the below event when I check or uncheck it.</p>
  
  <pre><code>protected void CheckBox1_CheckedChanged(object sender, EventArgs e)
  {
      if (CheckBox1.Checked)
      {
          preContactTextBox.Visible = true;
          prePracticeCodeTextBox.Visible = true;            
      }
      else
      {
          preContactTextBox.Visible = false;
          prePracticeCodeTextBox.Visible = false;            
      }
  }
  </code></pre>
  
  <p>It is not entering this event at all. What I am doing wrong?</p>
  
  <p>here's the complete code:</p>
  
  <p><a href="http://pastebin.com/amQURr91" rel="nofollow">http://pastebin.com/amQURr91</a></p>
  
  <p>How can I get it to fire the event?</p>