how to add animated Progress Image inside Ajax

how to add animated Progress Image inside Ajax Auto complete extender textbox to represent loading of data.

For achieving this functionality i am using two different approaches for different versions of AjaxControlToolkit.dll


or this write the below mentioned javascript in head section of html markup of the aspx page

[code]
function ShowImage()
{
 document.getElementById('txtAutoComplete')
      .style.backgroundImage  = 'url(images/loader.gif)';

 document.getElementById('txtAutoComplete')
                    .style.backgroundRepeat= 'no-repeat';
                   
 document.getElementById('txtAutoComplete')
                    .style.backgroundPosition = 'right';
}
function HideImage()
{
 document.getElementById('txtAutoComplete')
                      .style.backgroundImage  = 'none';
}


[/code]

Now write this code in Page_Load event of aspx page

[code]

protected void Page_Load(object sender, EventArgs e)
{
 this.txtAutoComplete.Attributes.Add
                          ("onkeypress", "ShowImage()");
 this.txtAutoComplete.Attributes.Add
                              ("onblur", "HideImage()");
}
[/code]

use toolkin html Code
[code]
<ajaxToolkit:AutoCompleteExtender runat="server"
                ID="AutoComplete1"
                BehaviorID="autoComplete"
                TargetControlID="txtAutoComplete"
                ServicePath="AutoComplete.asmx"
                ServiceMethod="GetCompletionList"
                MinimumPrefixLength="1"
                CompletionInterval="10"
                EnableCaching="true"
                CompletionSetCount="12"
                CompletionListCssClass=
                "autocomplete_completionListElement"
                CompletionListItemCssClass=
                "autocomplete_listItem"
                CompletionListHighlightedItemCssClass=
                "autocomplete_highlightedListItem"
                onclientpopulating="ShowImage"
                onclientpopulated="HideImage">
           </ajaxToolkit:AutoCompleteExtender>

[/code]