// Correct the time-string

function timeCorrect(timestring) {
  console.log(timestring);

  var re = new RegExp(timestring);

  if (/\d\d:\d\d:\d\d/g.test(timestring)){
    var array  = timestring.split(":");
    var secs = Number(array[2]);
    var mins = Number(array[1]);
    var hours = Number(array[0]);

    if(secs>59) {
      mins += Math.floor(secs/60);
      secs = (secs%60);
      if (secs < 10){ secs = "0" + secs; }
    }
    if(mins>59){
      hours += Math.floor(mins/60);
      mins = (mins%60);
      if (mins < 10){ mins = "0" + mins; }
    }
    if(mins>24){
      hours = (mins%24);
      if (hours < 10){ hours = "0" + hours; }
    }
    console.log( hours + ":"  mins + ":" + secs);
  }
  else if ( timestring === ""){
    return "";
  }
  else {
    return null;
  }


}