Javascript String toMMSS()

String.prototype.toMMSS = function () {
    var sec_num = parseInt(this, 10); // don't forget the second param
    var hours   = Math.floor(sec_num / 3600);
    var minutes = Math.floor((sec_num - (hours * 3600)) / 60);
    var seconds = sec_num - (hours * 3600) - (minutes * 60);

    if (hours   < 10) {hours   = "0"+hours;}
    if (minutes < 10) {minutes = "0"+minutes;}
    if (seconds < 10) {seconds = "0"+seconds;}
    var time = minutes+':'+seconds;
    return time;//w  w w.j a  v  a2  s  . c  o m
}

String.prototype.toMMSS = function () {
    var sec_num = parseInt(this, 10);
    var hours = Math.floor(sec_num / 3600);
    var minutes = Math.floor((sec_num - (hours * 3600)) / 60);
    var seconds = sec_num - (hours * 3600) - (minutes * 60);

    if (seconds < 10) {
        seconds = "0" + seconds;
    }//from www . j a va 2 s  .  com
    var time = minutes + ':' + seconds;

    return time;
};