Remember the eurocrisis? Last autumn it looked like the single European currency, which had drifted steadily downward from its January 1999 launch, was set for a freefall. But now that America's go-go economy is starting to flag, making the dollar appear less invincible, the little currency that could is stealthily inching back up. Last week, after debuting in Greece, the euro reached 95 cents, the highest level since July.So the worst it over, right? "Actually, the best is over," argues Steven Englander, currency economist with Citibank in London. After all, the euro is still hostage to what goes on across the Atlantic. And with Fed Chairman Alan Green- span dropping his bombshell of a rate cut last week to fend off recession, Englander and other pundits think the United States may look bleak for only a couple of quarters. With the European economy poised for a slowdown of its own, it probably won't be long before market players start betting on the dollar again.