How Do I: Use the ASP.NET AJAX DynamicPopulate Extender?

Hi,

I have been dynamic populate extender and its working in IE. But when i run it in Firefox it doesn't work. I get "Web Service call failed: 500" error. In IE its been working. I have used mostly the code available in tutorial only change is that i had to specify behaviorid to get it working.

Rest is pretty similar to Tutorial code.

Here is the code that i am using

<script type="text/javascript" language="javascript">

           function showSellerName(value){

               if (value != ''){

                   var behavior = $find('dp1');

                   if(behavior){

                       behavior.populate(value);

                   }

               }

           }

</script>

<asp:TextBox ID="txtSellerId" runat="server" MaxLength="12" Width="100px" onfocusout="showSellerName(this.value)"></asp:TextBox>

<ajaxToolkit:DynamicPopulateExtender ID="dp1" runat="server" ServiceMethod="GetSponsorName" TargetControlID="pnlSponsorName" PopulateTriggerControlID="txtSellerId" CacheDynamicResults="true" BehaviorID="dp1" UpdatingCssClass="dynamicPopulate_Updating" >

               </ajaxToolkit:DynamicPopulateExtender>

Please advise me what should i do to get it working in firefox as well.

Thanks.