Should I resign from current employer before h1b visa interview

I am currently working with company A . in january 2015 I got an offer from company B who has filed a H1B visa for 2016 and got approved . previously I did not have any US work visa.My question is when should I resign from my current job before visa stamping or after visa stamping?

Because during stamping if they ask for experience letter for last employer then what should I show if did not resigned from current organization.

Please help


You are not required from current employer before appearing for visa interview.

Carry your update resume where you mention the current tenure as on-going. Typically they don’t ask for old experience letters unless they have doubts about the authenticity of your work experience. Also, they understand that people do not resign from current employers when they appear for interview. So they don’t ask for experience letter from your current organization.