Euro cheques, electronic transfers, banking, etc.) at midnight on 1 January 1999, when the national currencies of participating countries (the eurozone) ceased to exist independently. Their exchange rates were locked at fixed rates against each other. The euro thus became the successor to the European Currency Unit (ECU). The notes and coins for the old currencies, however, continued to be used as legal tender until new euro notes and coins were introduced on 1 January 2002. The changeover period during which the former currencies' notes and coins were exchanged for those of the euro lasted about two months, until 28 February
International status and usage of the euro standing, mostly at the expense of the dollar. The increase of 4.4% in 2002 is due to the introduction of euro banknotes and coins in January 2002. The possibility of the euro's becoming the first international reserve currency is now widely debated among economists. Former Federal Reserve Chairman Alan Greenspan gave his opinion in September 2007 that the euro could indeed replace the US dollar as the world's primary reserve currency. He said it is "absolutely conceivable that the euro will replace the dollar as reserve currency, or will be traded as an equally important reserve currency." In the second