Fisher-Yates shuffle in js

shuffle.js

// using http://en.wikipedia.org/wiki/Fisher-Yates_shuffle

function randrange(i) {
  return Math.floor(i*Math.random());
}

// in-place shuffle
function shuffle(items) {
  var tmp;
  var i = items.length - 1;
  while(i >= 1) {
    j = randrange(i);
    tmp = items[i];
    items[i] = items[j];
    items[j] = tmp;
    i -= 1;
  }
}