I am going to get a re-entry permit at the airport, but my friend told me that I have to show the officer an return ticket in order to get a re-entry permit(he is not sure). and how long it takes to finish the re-entry process at the airport? Thanks !

I don't believe you need a return ticket, you DO need photographs as there are no facilities at the airport (if anyone can update on this it would be handy).

The process can take up to an hour if they're busy and you can't do it until you've checked in, so be there when the check-in desks open.

The permit desk is inside the central buffer hall (where you queue for outgoing immigration) there's a big sign outside with the requirements and process.

I am not aware of any ticket requirements for a re-entry permit.

If I were you I would not leave matters to the last minute at the airport,

much better to apply at a local immigration office, if there is one close to where you stay.

One photocopy of the passport, ID page and current visa page, and two photos, if I remember correctly.