MarvinXu

function commfy0(n){
    var a = n.toString().split(".");
    var i = a[0].length%3;
    var prefix = (a[0].substr(0,i)+a[0].substr(i).replace(/(\d{3})/g,",$1")).replace(/^,/, "");
    //var postfix = a[1] ? "."+a[1].replace(/(\d{3})/g, "$1,").replace(/,$/, "") : "";
    return prefix+(a[1]?"."+a[1]:"");
}