H1B Transfer: Is the Old H1B Valid

[welcomehome]

Hello Everybody,

I have a question about H1 B Transfer. Does anyone have an idea that if

I transfer my existing H1B to another company, does my old H1B get

canceled. Does that mean I wont be able to work for my old company?

Also if the old H1B also remains in status even after tranfer to

another company, do I have a restrcition on number of companies to

which I can transfer the H1B?? Can I transfer my existing H1B to two

different companies at same time??

Thanks