How do I know if employer has revoked my I-140

[Shloka]

1>My 140 was approved 4 years back.
2>I filed my 485 in July 2007


Now my employer is not behaving well(not answering phone call etc..)

HOW CAN I KNOW OR IS THERE A WAY FOR ME TO KNOW IF HE HAS REVOKED MY 140?

PLEASE ADVICE....

GINNU,and other GURUS..

[angela20]

The old employer can revoke I-140 and alarmingly, USCIS has recently taken the position that the PD will also be lost.