我在A公司的perm 申請出了點問題，B公司給了offer，並且說我上班後馬上給我辦perm。請問：
1. 如果我已經開始在B公司上班，而且B公司的h1b transfer petition 也被批準，我在等B公司perm的時候，還可以回A公司嗎？
-Yes if A Company have not requested USCIS to revoke/cancel your H-1 status yet.
2. B公司的petition一通過，A公司的 original h1b 就自動作廢了嗎？
-No. But by immigration law, A compnay will request USCIS to revoke your H-1 status sponsored by them, which of course does not affect your status to work for B Company.
3. A和B可以同時給同一個外籍勞工辦理perm嗎？
-Yes. But the problem is that one of the compnanies will be angry because the company cost a lot of money (filing fee, lawyer fee,etc.) and energy to do the H-1 and PERM petitions for you. Then, you will not work for them after they do the H-1 and PERM for you, and they have to find anther person to file the position which takes time and enery also.
