definiens: under the Public Health Service Act, as defined in 42 U.S.C.(Section ) 256b(a)(4 ) ( a ), which sales occur between the ClosingDate and that last day on which sales prior to the Closing Date are the basisfor the price to be paid by such PHS Entity pursuant to 42 U.S.C. ( Section)256b(a ), the [COMPANY] Companies shall pay to the Acquirors an amount equal to thedifference between the average manufacturer price for Skelaxin for the calendarquarter ended March 31, 2003 and the amount required to be paid by such PHSentity pursuant to 42 U.S.C. ( Section ) 256b(a ) for any such sales . The ElanCompanies shall make such payments to the King Companies from time to timewithin ten ( 10 ) Business Days after the receipt by the [COMPANY] Companies ofdocumentation reasonably sufficient to document such payments and such otherdocumentation as the [COMPANY] Companies may reasonably request with respect to suchsales