Prototype JS Framework - Calling a function when updates occur with a periodic updater.

Question

How do I call a function on every update? Below is what I tried. It doesn't work. The function itself works fine when I execute it alone.

new Ajax.PeriodicalUpdater('chatMessages', 'chat/receive_chat',
        {
                method: 'post',
                parameters: {lId: latestId},
                insertion: Insertion.Bottom,
                frequency: 2,
                decay: 2,
                Onsuccess: val = function(){$('chatMessages').scrollTop = $('chatMessages').scrollHeight;}
        });

Answer 1

You have an assignment for onsuccess. What you need is either a reference to a function or inline function.

onsuccess: function(){$('chatMessages').scrollTop = $('chatMessages').scrollHeight;}
// or
onsuccess: my_callback_func

Answer 2

Is this as simple as a case-sensitivity issue?

You have:

Onsuccess: function(){...}

Should it be:

onSuccess: function(){...}

Answer 3

Here is a working example: JSFiddle Example