Thank you very much, Mr. Pjiang.
As I changed status before in the U.S., from B1 to F1, then to H1. I am afraid to go abroad to apply for visa may have some trouble. That's why i think of the possibility to convert to H4 and then switch back to H1, At least I will be in the U.S. with the family.
Any thoughts,
Thank you again for the prompt response.