This excerpt taken from the ADVS 8-K filed Sep 5, 2008.
Withholding Taxes. The Company, Parent, the Surviving LLC, and the Escrow Agent shall be entitled to deduct and withhold from any consideration payable or otherwise deliverable pursuant to this Agreement to any Person such amounts as may be required to be deducted or withheld therefrom under any provision of U.S. federal, state, local or non-U.S. law, and to request any necessary tax forms, including Form W-9 or the appropriate series of Form W-8 as applicable, or any similar information, from such person. Any such amounts shall be withheld or deducted from the cash consideration payable, provided that if such cash consideration is insufficient to satisfy the full amount to be withheld or deducted, the remainder shall be satisfied out of the stock consideration issuable. The number of shares of Parent Common Stock, if any, to be used to satisfy the remaining amount required to be so deducted or withheld shall be determined by dividing such remaining amount by the Trading Price, rounded to the nearest whole share (with 0.5 of a share rounded up). To the extent such amounts are so deducted or withheld, such amounts shall be treated for all purposes under this Agreement as having been paid to the Person to whom such amounts would otherwise have been paid.