ICallBackEventHandler examples for

Hi Friends,

I have 3 dropdownlist(they are not related to each other) in the page and they are set to autopostback="true".
If I select an option from the each dropdown I have to show panels with containing some fields(textboxes, buttons, etc..). So to avoid page refresh I kept all of them in the updatepanel and
there is updateprogress control to  show precessing text.

But the problem in the production server is for each dropdown selection the user has to wait for some time.

I am planning to switch to ICallBackEventHandler to avoid the processing time.

I googled alot for this but I didn't success.

I need some good example and resources to solve the problem.

Thanks,
Farooq
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