title: Bootstrap modal closes when dropdownlist inside fires selected index changed event
body: <p>I have a ASP.NET chart inside a Bootstrap modal.</p>
  
  <p>Everything was working fine until I added a dropdown list inside, every time I select a new item in dropdown list the selected item changed event fires, and Boostrap modal closes, event if there is no code inside event.</p>
  
  <p>Here is the modal bootstrap html:</p>
  
  <pre><code>&lt;div class="modal fade" id="modalCantidadReservasMensuales" tabindex="-1" role="dialog"
      aria-labelledby="myModalLabel" aria-hidden="true"&gt;
      &lt;div class="modal-dialog"&gt;
          &lt;div class="modal-content"&gt;
              &lt;div class="modal-header"&gt;
                  &lt;button type="button" class="close" data-dismiss="modal"&gt;
                      &lt;span aria-hidden="true"&gt;&amp;times;&lt;/span&gt;&lt;span class="sr-only"&gt;Close&lt;/span&gt;&lt;/button&gt;
                  &lt;h4 class="modal-title" id="myModalLabel"&gt;
                      Cantidad reservas mensuaCantidad reservas mensuales
                  &lt;/h4&gt;
              &lt;/div&gt;
              &lt;div class="modal-body"&gt;
                  &lt;asp:DropDownList ID="ddlAñoCantidadReservasMensuales" runat="server" OnSelectedIndexChanged="ddlAñoCantidadReservasMensuales_SelectedIndexChanged"
                      AutoPostBack="True"&gt;
                  &lt;/asp:DropDownList&gt;
                  &lt;asp:Chart ID="Chart2" runat="server" Width="441px"&gt;
                      &lt;Series&gt;
                          &lt;asp:Series Name="test1"&gt;
                          &lt;/asp:Series&gt;
                      &lt;/Series&gt;
                      &lt;ChartAreas&gt;
                          &lt;asp:ChartArea Name="ChartArea1"&gt;
                          &lt;/asp:ChartArea&gt;
                      &lt;/ChartAreas&gt;
                  &lt;/asp:Chart&gt;
              &lt;/div&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>