I140 approved - Employer change

[iamimmi]

I am on H1B. I140 with company A is already approved. PD - Jun'06. I am already running in 7th year. Extension of 3 years is already filed.

Trying to get substitute labour with company B, which would enable me to file I140/485. Question is:
If I140 with company B gets in problems or denied, can I join back to company A by keeping my priority date i.e. I140.
Suggestions please.
Thanks.

[ghiegelo]

how can you file your I-140 and I485 if your PD or vis number is not current?