L1B to H1 - Queries

[ersum_max]

Thanks to timely answers from the members of the forum.

I am currently on L1B from company A working in US on a assignment. Company B is filling H1 April 2007.

I have following questions:

1. Is it mandatory to stay in US till my H1 petition is approved ?

2. Where will I need to get my H1 stamped ? (In home country or Mexico/Canada )

3.If my assignment finishes before I recieve my H1 petition approval notice and I am asked to travel back to home country by my current employer , what happens to my H1 application ?

4. Once I get the Petition approval notice , till when can I continue on L1 ?

5 Do I need to get the H1 stamped within a fixed number of days after the approval arrives ?

Thanks in Advance,
Max