How do I modify just one instance from a recurring event sequence.
Right now if I make changes to one of the event in the sequence, the whole sequence gets updated.
How can I have a option to separate the selected instance as new calendar event?

Hi,
for instance you can store some flag in "Extensions" property of calendar item (as it is done now in web-sample). In web-service method "UpdateItem" you should check this flag. If it is "true" you should treat with the item as with recurring one. If it is false item is not recurring.

Thanks,
If a user is dragging or delete a recurring event then I want to popup a message asking him if he wants to modify the whole recurring sequence or just this event. And depending on  his response I would set a flag in "Extensions" property of the calendar item.
This has to be done on the client side using Javascript. Do you have any example how I can achieve this and also interact with the Calendar item on client side.
Or is there a better way you might know?

Hi,
you should register your own client side event handlers for calendar control. Please read the documentation section about it: http://docs.mediachase.com/doku.php?id=calendar:30:api#handling_client_side_events. In your handler(s) second parameter "args" will contain all information about calendar item (Uid, Title, StartDate, EndDate, etc.)

Hope this helps.