Hi. My H1B got approved during 2016 and my employer filed LCA for a different location when i was in India and it was approved during May 2017. I got receipt notice, with that i travelled to USA on July 2017 for the new location. Still i didn't receive the I 797B for the latest LCA which was approved. My employer is going to file a request to get the duplicate LCA as it was missed. Now i am planning to change my Employer to another, can i do that with my old petition as i don't have the latest I797B or i have a receipt number and receipt notice. Is that sufficient?