<Is it possible to change jobs if I don't have this information?>
YES. The only problem is you have to prove to INS that you have same or similar new job. So, you need the job title and description in your Labor/ I-140.
1. You can hope that your H1 job description was same. You may use that.
2. DOL has public database of all LCs and LCAs...since 2000.
Go to
www.flcdatacenter.com and you will see downloadable mdbs. You can get your job title for which Labor was filed, and the job code. find out typical job description from Onet or Dot dictionary and you have your old job description.
3. Foramlly, ask your employer about your job description. If they refuse, go to Dept of Labor, and they will have to.
4. Get new job title and job description accordingly.
5. There are really very nice AC21 letters on the board. Pick up a good one and send it to INS.
6. Thumb your nose to old employer and tell to shove up the I140 and labor where sun does not reach...
Best of luck, pal! I was in the same boat..I asked Rajiv, but he said I may not be able to defend potential NOID with out job description. None of the boards IV or Murthy or trackitt told me how to get job description, so I found myself (and I am patting myself on the back

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