| No short-term investments as of December 31, 2007 or 2006 had maturities over 3 months. |
| Cash and cash equivalents |
| Short-term investments with maturities up to and including 3 months are combined with Cash and bank to produce the item Cash and cash equivalents, as follows. |
| The carrying values are assumed to approximate fair values as the risk of changes in value is insignificant. For more information on financial instruments by category and exposed to credit risk, see Notes 22 "Financial Assets and Liabilities by Category" and section "Credit risk management" in Note 23 "Financial Risk Management," respectively, and to Note 25 "Contingencies, Other Contractual Obligations and Litigation" for information on blocked funds in bank accounts. |