目前是有I797, 不知道如果去加拿大的话，
-Is that I-797 is H4 approval notice? If yes, that I-797 is useless because your H4 I-94 has expired. You need to bring your spouse's H1 approval notice to get the H4 visa outside US as you did in China last time.
是否可以
1.） Submit I-94 when leave U.S
-Yes, must.
2.) Come back without new H4 visa since we have I797 paper,
which expires on March 2012. Heard from attoney that there
is 30-day rule when travel to Canada.
-That does not apply to your case because your I-94 has expired.
如果实在不行， 只好现在预约美国驻加拿大使馆， 签证了。
-Must. When you get the H4 visa to come back and get the new H4 I-94 at the port of entry, your status will be re-counted and have no gap at all.
