Change owner of event google calendar

Hi,

Has any way to change owner of google calendar event.

I'm using GOAuthRequestFactory to call CalendarService by service.Requestfactory

I get entry by (eventid, email, requesfactory) after that i clear old author and add new author typeAtomperson again.

It update successfully, but when i get evententry again, the author do not change.

Any body tell me why? Is there another way to do it?

And any help will be appreciate.