I did install the wrong zip file and I did get it working.

I also referred to the wrong piece of code and not your HelloAjax.

I have been trying to get my code working and using HelloAjax as a reference. What differs my code from yours is that I do not have an "onclick" event rather am using:

string cbReference = ClientAPI.GetCallbackEventReference(this.Page, "'arg'", "ReceiveServerData", "this", "Image_Error");
string callbackScript = "<script language=javascript >function CallServer(arg, context)" + "{ " + cbReference + "}</script>";
ClientAPI.RegisterClientScriptBlock(this.Page, "CallServer", callbackScript);

ReceiveServerData and Image_Error are javascript functions. I have a javascript timer event that calls CallServer.

What I am trying to work through now is an "object required" error on function __doPostBack(eventTarget, eventArgument)

I have seen other people ask questions about using a callback with no actual event such as onclick. I have yet to see any example code that I could actually use as a good reference. Certainly your ClientAPI - Client Callback material does not cover what I am describing.

Thanks Jon, I finally got things working with your help. It just does not get more complex than working with these features in DNN. I've been trying to get the basis working with what I am trying to do and I feel like I have just scratched the surface.