ADDENDUM FOR EMPLOYEES IN AUSTRALIA

TAX INFORMATION

         This summary does not discuss all of the tax consequences that may be
relevant to you in your particular circumstances, but is merely intended to
alert you to some of the tax information you may want to consider in making your
decision.

         If you surrender your eligible options pursuant to the terms of the
offer, you will be deemed to have disposed of your eligible options as
consideration for the right to receive new options. In general, the tax
treatment depends on whether you elected to include the discount (I.E., the
market value of the eligible options at the time of grant) in your assessable
income for the income year in which such eligible options were granted. If you
did not elect to include the discount in your assessable income for that year,
then you will be required to recognize income equal to the market value of the
right to receive the new options as at the date of the exchange. If you did
elect to include the discount in your assessable income, then you will derive a
taxable capital gain equal to the market value of the right to receive new
options at the date of the exchange less the cost basis of the eligible options,
as applicable (subject to reduction by one-half if you have held the options for
at least 12 months). You may be subject to taxation on the exercise of the new
options and/or capital gains tax on the sale of the shares acquired upon the
exercise of the new options. However, the tax payable on account of the option
exchange may result in a reduction of the tax payable on the exercise of the new
options or the sale of the shares acquired upon the exercise of the new options.

         Please note that tax laws change frequently and vary with your
individual circumstances. Please consult a tax advisor to determine the tax
considerations and tax consequences relevant to your participation in the offer.