生日转年龄

function birthday2age($birthday='1949-10-01'){
	list($year,$month,$day)=explode('-',$birthday);
	$year_diff=date('Y')-$year;
	$month_diff=date('m')-$month;
	$day_diff=date('d')-$day;
	if($day_diff<0||$month_diff<0)$year_diff--;
	return $year_diff;
}