h1b visa stamping using future employer I797, while still working with current employer

USA H1B Visa
1

Hi

My current visa is till Aug 2015this is my 6th year) with greencard I140 approved

I am currently in Company A, and have an offer from company B. They are filing for h1b transfer under premier and because of my I140 approval they told I can get 3 years automatically

I need to travel to India for a wedding next month

Assuming I got aproval by then, can i go for visa stamping in India showing my future employer I797 approval while still working with my old employer?

I am planning to come to Usa and then quit

2

Hi

Can you tell me your status on this. I am in india and have to go for h1b transfer visa interview with employer 2 before reliving employer 1.would like to know the chances.