Filling I-485 for wife after PD gets current.

[nkgupta77@yahoo.com]

My Perm was filed on Dec 2009 and the current Priority date is 1 Jan 2009. I have some questions regarding this and would appreciate if any one can provide me some information.

1) Is it true that one should have to be in US to file for I-485? My wife will be going to India for a year for an international assignment in Feb 2012 and what happens if priority date becomes current prior to her coming back in 2013?

2) If one should have to be physically in US to file for I-485, can she come back on H-4 or Business / visitor visa for a week to file for I-485 or she has to stay in US until and unless we get a green card. What would be the minimum periord she has to stay in US for filling I-485?

Please advise me the options if the priority date becomes current before my wife back form India.