Thank you for answering my question several days ago. I have to be cautious so one more question: As my previous post, if I quit my current job and use EAD to work as a RA in the same university with same boss(that sponsored my current H1b) and study full time as PHD student, you said that 'Completing a PhD in the same field is difference from working in the same field.'. Do you mean I have to keep my full-time employment to be safe? Would you please explore further? What are the possibile reactions INS would have--request for employment letter? Is my RA employment letter (half-time) sufficient?
Thanks.