H1 B Prior Employment Documents query - Urgent

[sensedan]

Hi,

This is the first time I am applying for H1 B visa. Regd documents submission, I do not have prior employment service/experience letter. But I have an acknowledgement letter of my resignation from previous employer. Is it Ok to submit this acknowledgement letter instead of service letter for visa processing? I am confused and it is very urgent!

Please help me on this guys!

Thank you!