Reg. H1B Application

[immihelp]

Hi,

I was going through your website, which I find it very useful the FAQ Section for H1B.
I have a small query though.

Actually, I hold a valid H1B visa for the employer, Company-A, but I never travelled to USA as the project got postponed and later there was no requirement.
I have now applied for the New H1B visa through different employer, Company-B, I got the I-797 also now for the new H1B petition through company-B.

My Questions are as follows...

1. Do I need attend for the H1B visa interview again though I got the one valid H1B already from previous employer?
2. If I need to attend for the H1B interview in Mumbai consulate as it is a different employer, What documents do I need to carry to the interview? Do I need to carry the previous I-797 also which I got for my first H1B?
3. If I got the new visa issued, will the previous visa gets cancelled?
4. If the new H1B visa gets rejected, what will happen to old H1B visa?
5. Also, tell me, Can one individual hold same class of visa, I mean 2 H1B visas on one's individual passport? I mean can any one hold 2 H1B visas at the same time on the different employers?

I would be greatful if you can clarify my doubts, and thanks very much indeed.

Thanks

[immihelp]

1. Yes.
2.
A. The same as before for the new employer.
B. Yes, carry previous I-797.
3. No, but if the employer A does not want you work for them, it is meaningless.
4. That depends upon the reason for rejection.
5. Yes.