H4 to H1

[thanvi]

My wife came to US on H4 in March 2007 and she is selected in the lottery for H1 in 2007. She did not get an approval yet as there is a query.

She is planning to travel to India for around 4 weeks.

Can she come back on H4 visa to US if her H1 gets approved while she is in India?
Can she start working without going for H1 visa in case her h1 gets approved while she is in Inida?
Can she start working without going for H1 visa in case her H1 gets approved after she returns to US on H4?

Please answer ASAP.

Thanks in advance.
Prabhu