// http://en.wikipedia.org/wiki/Ordinal_number_(linguistics)

function toOrdinal(n) {
  var tens = Math.round((n % 100) / 10);
  var ones = n % 10;
  var suffix = 'th';
  if (tens != 1) {
    switch(ones) {
      case 1:
        suffix = 'st';
        break;
      case 2:
        suffix = 'nd';
        break;
      case 3:
        suffix = 'rd';
        break;
    }
  }
  return n + suffix;
}