out of US stay of more than a year on GC?

[javaxmlsoapdev]

My mother recently got her green card on relative basis (USC sister). She is flying to India in few days and not planning to come back for next 2 years. In order to get permit(to stay out of US for more than a year) from USCIS, which form I should fill up and send to INS? I believe this needs to be done before she leaves US? Please advise.

 

[civ2ru]

"Permanent residents who leave the United States for extended periods, or who cannot show their intent to live permanently in the U.S., may lose their permanent resident status. If you think you will be out of the U.S. for more than 12 months, you should apply for a re-entry permit before leaving the country. You should file Form I-131, Application for a Travel Document. A re-entry permit is valid for up to 2 years and shows that you are returning from a temporary visit abroad. You may show the re-entry permit at a port of entry."