3.7 Non-operating land Non-operating land is stated at the lower of cost and latest appraised value. 3.8 Impairment of assets Assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Whenever the carrying amount of an asset exceeds its recoverable amount, an impairment loss is recognised in current operations. 3.9 Treasury stock Treasury stock is stated at cost and presented as a reduction from shareholdersâ€™ equity. Gains on disposal of treasury stock are determined by reference to its carrying amount and are taken to premium on treasury stock, losses on disposal of treasury stock are determined by reference to its carrying amount and are taken to premium on treasury stock and retained earnings, consecutively. 3.10 Foreign currencies Transactions in foreign currencies incurred during the year are translated into Baht at the rates ruling at the transaction dates. Monetary assets and liabilities denominated in foreign currencies outstanding at the balance sheet date are translated into Baht at the rates ruling at the balance sheet date except for those covered by forward exchange contracts at the contracted date. Exchange gains and losses are included in determining earnings. Discounts or premiums on forward exchange contracts (the difference between the spot exchange rate and the forward exchange rate at inception of the contracts) are deferred and amortised to earnings over the contract lives using the straight-line method.