[url=file://\\d)(\\d{3})(,|$]\\d)(\\d{3})(,|$[/url])");
while(re.test(b)){
b = b.replace(re,"$1,$2$3");
}
return a +""+ b +""+ c;
}
var num=1234567/3;
alert("num="+num+",四舍五入:"+Math.round(num)+",两位有效数字:"+num.toFixed(2)+",添加千位分隔符:"+formatNumber(num));
</script>