You can directly attach the client onclick event to the LinkButtons for update/insert. Then in the event handler (for update button) access the RadGrid and get the selected item and keyvalue from client side. You can use the following client code to get the selected row.
|var grid = $find("<%=RadGrid1.ClientID %>"); |
|var MasterTable = grid.get_masterTableView(); |
|var selectedRows = MasterTable.get_selectedItems(); |
|var row = selectedRows; |
Then open the radwindow using same approach described in the online demo, by passing the parameters.
Please let me know if you have any doubts in my suggestion,