Mon Aug 24, 2009 11:39 am
If you are laid off or quit, the employer must notify USCIS within a certain period of time and your status is invalid at that point and you must leave the US "immediately" which is generally interpreted as ten days.
You can switch employers by having the new employer file an I-129 for you to change status to them, the trick is to not have a gap. It doesn't alter the maximum validity of the H-1B, it's six years assuming you qualify for renewal after three, changing employers doesn't matter.
Steve.