I am currently in country on a dbl entry tourist visa issued in Vientiane. Now I will have to go to a job interview to another Asian country next week, so I need a re-entry stamp from the immigration.

Questions:

1. Which immigration issues it? Is it the "new" one in Chaeng Wattana? Or the "old" one in Suan Plu?

2. How much does it cost? How much time does it take? What information/documents do I need to bring other than my passport?

3. Will they issue the re-entry stamp or could there be any problem because of the red warning stamp in my passport saying that I travelled to Thailand on a tourist visa several times?

1. If in Bangkok Chiang Watanna, or old Suan Phlu office on Saturday morning, or airport during day/evening if you have to.

2. 1,000 baht and about 15 minutes. Photo, copy of passport data page/visa/entry stamp and arrival card will likely be required (and the application form).

3. Should not be an issue.

or airport during day/evening if you have to.

That's a good info: Does it mean I can just get it at the airport before taking my flight? I actually don't have much time now, so it would save me the hassle of going to the immigration.

Airport desk is only open 06-2400 I believe and only available for departing pax so time could be a factor. If using be sure to have photo and copies. Believe fee is an extra several hundred baht (over the 1 or 3.8k normal price) also so be sure to have the baht with you. Always best to obtain before travel - you have enough to worry about just keeping security happy these days.