Reltub,

To simplify this process, being on an Exchange service using Activesync would solve your issue. Microsoft Exchange service will allow you to sync that Iphone to your mailbox and have it synchronize contacts, calendars and mail in real time.

However, since it is not clear if you are on this service, below is a link with the information you require,

http://www.ehow.com/how_2313206_sync...-calendar.html

Hope this helps.