Please let me know the valid perid I should leave after I get the re-entry visa. I got the re-entry visa last month but the trip was canceled and I didn't leave the Kingdom. Do I need to re-apply for the re-entry visa for my next trip again? Or do I need to report something about the re-entry visa to the immigration office if I continue to stay as usual?

Thanks.

Believe you are talking about a single re-entry permit (is not a visa) which is good for use any time during your current permission to stay. It is not linked to a specific trip, and you do not need to report non-use to Immigration. When used it will simply preserve the expiry date of your current permission to stay on re-entry into the Kingdom.

The date should be on the re-entry permit itself I believe and as said would the the permitted to stay date that you had when it was obtained so can be used up until that date.

Thank you so much for your replies.

It's said Valid Until 11 August 2012, the expiry date of my stay permit. So, let me know it means that I can go and come back before that date to keep my stay permit?

Thanks again.

Yes that is what it means. If single entry only once - if multi entry any number of times.