I am in U.S on an H1B.
My wife is working for an IT firm in India. Her company has applied for an H1b for April cap 2012 and she would be getting her approved petition in a week. Her h1b start date would be october 1 2012.
In the meantime we have decided that my wife is going to take a break and we planned to get a h4 visa for her and she would be going for stamping next week. if everything goes well she would travel to US next week on H4.

So my question is in that case what happens to her VISA status on October 1(the day when her H1B validaity starts) since she would be in U.S on H4 at that time.

Thanks for you help.