How long can a person with a US Temporary Permanent Resident Visa (Green Card) stay out of the US before their visa status expires? How do you reapply for it, after it expires? Does the US visa holder or the US petitioner re-apply for it?

What/how does a US petitioner do to cancel a US Visa application?

1. Green card holders should not leave US longer than 6 months a year.. and during the process of renewal/removal of condition, you must stay in US.

2. If you have conditional green card, you must file I-751 within 90 days before expiration date. Details : How Do I Remove The Conditions On Permanent Residence Based On Marriage? (http://www.uscis.gov/portal/site/uscis/menuitem.5af9bb95919f35e66f614176543f6d1a/?vgnextoid=7b6d96981298d010VgnVCM10000048f3d6a1RCR D&vgnextchannel=2f719c7755cb9010VgnVCM10000045f3d6a1 ____)