title: Warning AjaxControlToolkit.AutoCompleteExtender.CompletionListElementID is obsolete: Instead of passing in CompletionListElementID, use the default
body: <p>I really can not understand this problem. When i publish my asp.net 4.0 website it shows this error.</p>
  
  <p><strong>Warning   'AjaxControlToolkit.AutoCompleteExtender.CompletionListElementID' is obsolete: 'Instead of passing in CompletionListElementID, use the default flyout and style that using the CssClass properties.'</strong></p>
  
  <p>Now i am going to provide the element it shows as warning.</p>
  
  <pre><code>   &lt;ajaxToolkit:AutoCompleteExtender runat="server" BehaviorID="AutoCompleteEx2" ID="AutoCompleteExtender4"
      TargetControlID="txtPokemonName" ServicePath="AutoCompleteName.asmx" ServiceMethod="GetCompletionListPokemonName"
      MinimumPrefixLength="1" CompletionInterval="500" EnableCaching="true" CompletionSetCount="25"
      CompletionListCssClass="AutoExtender" CompletionListItemCssClass="AutoExtenderList"
      CompletionListElementID="DIVAutoExtender2" CompletionListHighlightedItemCssClass="AutoExtenderHighlight"
      DelimiterCharacters=";, :" ShowOnlyCurrentWordInCompletionListItem="true"&gt;
      &lt;Animations&gt;
          &lt;OnShow&gt;
              &lt;Sequence&gt;
                  &lt;OpacityAction Opacity="0" /&gt;
                  &lt;HideAction Visible="true" /&gt;
                  &lt;ScriptAction Script="
                      // Cache the size and setup the initial size
                      var behavior = $find('AutoCompleteEx2');
                      if (!behavior._height) {
                          var target = behavior.get_completionList();
                          behavior._height = target.offsetHeight - 2;
                          target.style.height = '0px';
                      }" /&gt;
                                             &lt;Parallel Duration=".4"&gt;
                      &lt;FadeIn /&gt;
                      &lt;Length PropertyKey="height" StartValue="0" EndValueScript="$find('AutoCompleteEx2')._height" /&gt;
                  &lt;/Parallel&gt;
              &lt;/Sequence&gt;
          &lt;/OnShow&gt;
          &lt;OnHide&gt;               
              &lt;Parallel Duration=".4"&gt;
                  &lt;FadeOut /&gt;
                  &lt;Length PropertyKey="height" StartValueScript="$find('AutoCompleteEx2')._height" EndValue="0" /&gt;
              &lt;/Parallel&gt;
          &lt;/OnHide&gt;
      &lt;/Animations&gt;
  &lt;/ajaxToolkit:AutoCompleteExtender&gt;
  </code></pre>
  
  <p>Now what does visual studio want me to fix and why showing this warning ?</p>
  
  <p>Any ideas ? Thank you.</p>
  
  <p>Visual Studio 2010 , C# 4.0 , Asp.net 4.0 , Asp.net website</p>