H1B visa holder, Duration he can stay in US after job is terminated

[immihelp]

Dear immihelp,

Wonderful site.

How long can I stay in US if a person job is terminated. He need some time to have another employer.

1) I think he can stay till the I-94 is valid. Is this
assumption correct.

2) If say person is without job and no pay roll run for say 30 days. Then when he applies for Green card. Will this gap will be an issue. Or a person must go out of USA once his employment is terminated and
should file for H1 again from outside USA.

Please confirm. I have heard that the gap in a job during a stay in US on H1 cause several problem when you apply for Green card. Do the continuity to be in Job is must.

[immihelp]

There is no grace period if the job is terminated.