Expired I-797: Am I cap exempt?

[saushukla]

I have applied for H1B during the year 2007 for the quota of 2008. In the month of July-2007 my petition got approved. But due to some personal reasons, I have not used this H1B. I never went for VISA stamping and I never travelled on US on any type of VISA.

I also don’t have any document like approval notice or I797 with me, but I can get that from my employer

Now,

1) Can I use this expired petition to file for extension outside the quota?

2) Till what duration my H1B stays valid ?

3) Is the receipt number alone would be sufficient for the further processing ?

4) what all documents would be required from previous petition?