Attempting to convert a legacy ASPX page (that uses ICallbackEventHandler/RaiseCallbackEvent/GetCallbackResult) by way of a custom DNN module. I am a newbie to DNN and C#. Understand that the DNN module has to use IClientAPICallbackEventHandler and its method instead. Not sure of the correct implementaion of the DNN ClientAPI Client Callback event handling within a C# module. Can anyone please point me in the right direction / resources links / sample implementation.

Cathal,
Thanks a lot for your help. Will try to implement as per http://www.dotnetnuke.com/Portals/25/Documents/DotNetNuke%20Client%20API%20Client%20Callback.pdf . BTW are there any C# samples / documentations posted anywhere? Our pages have dynamically created 'TextBox' elements the values of which needs to be sent (as a concatenation of string values) across to the server for processing and receiving (a string as the) response from server for updating some page elements using a JavaScript function.

I am told that it would be much easier to use "Telerik controls" (such as RadAjaxPanel, RadAjaxManager..etc), that take advantage of AJAX to achieve asynchronous callbacks.
Is it the prefered solution when developing custom DNN modules? Should we make the additional investement in order to implement (simple) callback based processing?

Cathal,
Thanks a lot for your timely comment. I can now focus on taking advantage of (AJAXified)Telerik controls. If you have a minute plese let me know if the Telerik.Web.UI.dll thats shipped with DNN (5.2.2) is adquate to implement RadGrids and other Telerik controls under RadAjaxManager/RadAjaxPanel? Are ther any limitations that I should be aware of wrt the DNN's Telerik.Web.UI.dll?
Once again thanks a lot for your help.