> Hi Anand,
>
> Don't know about the invalid callback error. But there is a bug in the
> javascript that the framework pumps out to deal with callbacks - two of the
> javascript functions have unscoped variables used as for-loop indexers.
> They are both named i. You can greatly reduce your chances of getting the
> PendingCallbacks error by checking all of your own javascript for any
> variables named i, and changing them to something else (or scoping them as
> local variables by using the var keyword).
>
> S
>
> "Anand" <Anand@discussions.microsoft.com> wrote in message
> news:CCD6BEF2-812A-40B4-BDB0-8D90CDA05C2B@microsoft.com...
> > Hi
> > Season Greetings,
> >
> > I'm trying to implement client call backs in my page. i'm using user
> > controls (composite controls) and these are placed in my master page.
> >
> > I'm implementing ICallbackEventHandler and ICallbackContainer interfaces
> > in
> > my user control class to generate the callback, and i palced the
> > respective
> > javascript function in master page to receive results, and populated to a
> > asp
> > list box (typically i've to populate a list box on selection of a tree
> > node
> > in a tree view control)
> >
> > It is populating the list box however, after populating it is giving a
> > javascript error ("
> > _PendingCallbacks[...].async is null or not an object". i'm
> > generating/triggering only one callback(not multiple), Any clues how to
> > resolve this issue?
> >
> > Also, while posting back this form i'm getting "invalid postback or
> > callback
> > error" for the time being i've disabled the page "enableEventValidation" ,
> > any one solved this without disabling the validation?
> >
> >
> >
>
>