What is the criteria for a valid Vietnamese passport to use for F1 visa interview?

I'm going to have an interview for F1 visa interview to study in the United States soon in August. My Vietnamese passport is going to be expired in August, 2011. Do I have to renew my passport or is it ok to use my old passport for the visa interview? Thank you for helping.|||It has to be good for a minimum of 6 months from the time you enter the US. You should check with your Foreign Ministry to see how hard it will be to renew it after you get to the US. the maximum validity for a student visa for Vietnamese is only 12 months, so if you're planning to remain in the US for the next four years or you intend to both renew your visa and your passport if you go home next summer, you'll have to renew it in the US.|||You need to have a up to date passport for a visa. You may be OK for the interview, but apply for a new passport today and take proof you have done so with you.