Do I need stamping in Canada

[kannn]

Hi,
I've to visit my friend by 2nd week of august in Canada.
I would like to know if I've to get restamping in 1 of the US consulate if I visit.
Basically I came to US in H1 by employer A.
My passport stamping is with emp-A and it is valid until Sept-30-2007.And I've approved I-797 with emp-A which is valid untill 09-30-2007.
But few months later I've changed my employment to emp-B.And I've valid approved I-797 with this emp-B untill 02-03-2008.
I've never gone back to India after my first visit to US. And my I-94 is valid until Sep-30-2007.

Now since I'm visiting to Canada for 2 days do I've to get the staming in one of the US consultate in Canada when I come back.Some1 pls help me.I really need to make this trip.
I've heard that as long as I've H1 visa long enough I dont have to get the stamping even though I've changed my employer. Pls advise.
Also gona go to Toronto by flight. In this case where do I get the Canadian visa?

Thanks & appriciate ur response
Anand
Thanks
Anand

[veena_swsh]

If you have a valid H1B visa on your passport, then you don't need another visa stamping. You can re-enter on the old company's visa and show the new approval at the port of entry. Take also an updated letter from the present employer confirming your employment.

[kannn]

Thanks Veena.It helps.