changing status from h4 to h1 based on an already approved petition

USA H1B Visa
1

Hi,

I have an h1b petition which was approved in July 2013 (not yet stamped). I have a stamped h4 visa. I am currently in India. Would really appreciate if someone could help me with the following questions.

  1. Given that i already have an approved petition ,can i travel to the US on the stamped h4 visa ?

  2. If yes,what would be the process to change my status from h4 to h1 based on an approved petition ,and start working while in the US?