Change of status from H4 to H1B with I-797B

I am currently in H4 VISA and the I94 also has the same entry.

I also have an valid H1B petition (I797B) (Valid till Mar-2015), where stamping is yet to be done. 

 

I have few queries on my VISAs as below.

 

1. I red in few sites, where it says like person who has I797A petition can have change of status from H4 to H1, where I797B cannot do that. 

Please clarify

2. Do I need to go for stamping back to india, to continue work here?

3. In case if I need to go back to India for stamping, is it possible to have both stamping (i.e) for H1B and H4 extension?

4. I am currently seeking for job over here. Is there any way that I can go for a status change from my H4 to H1B, with the current I797B from US itself?

 

Please let me know if you need any more details to answer my queries.

 

It would be really great help if I get my queries clarified 

 

Thanks in advance

I also in the same situation and what to know the answers for the above questions.

It would be really helpful if someone can answer the same ASAP.