Interest on short-fall of FBT

Sec-115WJ(3) provides that when an assessee, has failed to pay the advance tax for any quarter or when advance tax paid by him is less than 30% the value of fringe benifit paid or payable in tha quarter, he shall be liable to pay simple interest @ 1% for the shortfall(FY-2006-07)------ in this case intrest is to be calcualted on FBT or FBT+Surcharge+Cess??