function a() {
var re = new RegExp("([0-9]{4})-([0-9]{1,2})-([0-9]{1,2})","ig");
var s="2003-1-6";
re.exec(s);
var year,month,day;
year=RegExp.$1;
month=RegExp.$2.length==1?"0"+RegExp.$2:RegExp.$2;
day=RegExp.$3.length==1?"0"+RegExp.$3:RegExp.$3;
alert(year+"-"+month+"-"+day);
}