Small queries in Schedule S in ITR2

Hi,

In ITR2, I have the following basic queries.

1. Throught the FY for which I am preparing ITR, I worked in only one company.  So do I need to fill up the Schedule S in ITR2 with that company details or is it required only if I worked in multiple companies?

2.  In this section, for S.1 (salary excluding all allowances, perquisites & profit in lieu of salary), should it include the sec 10 exempt of HRA and Conveyance allowance or not.  I mean, which one of the following formula is correct.

Schedule S. 1 = Gross salary - HRA - conveyance exempt

Ex:
Form 16: Gross salary = 300000  = A
Form 16: HRA + conveyance exempt = 25000  = B

Now S.1 = A - B  = 275000 (OR)
S.1 = A = 300000

PA.  Probably my question was not clear so I modified my question with clear explanation.
Please someone clarify my doubt urgently.

Thanks
Sakitram