How many days of valid visa required to enter USA

[summerpolice]

Hi
I got a L1 visa which expires on June 26 -2009.I am currently in US.I am planning to go to toronto next week.Just for a vacation .I havent applied any extension and i am planning to go to my home country after this .Is it advisable to go to canada .Is there any minmimum days of visa required.

Please advise.

Thanks