gistfile1.js

document.on('click', 'input[name="commit"]', function(evt, elm){
  var f = elm.up('form');
  fake_progress = new Element('div', {className: 'progress progress-striped active', style: 'width: 100%; clear:both'});
  f.insert({before: fake_progress});
  var bar = new Element('div', {className: 'bar'});
  fake_progress.insert(bar);
  bar.setStyle('width: 2%');
  var rnd = 0.2
  function add_random(){
    rnd = Math.random();
    var now = parseFloat(bar.getStyle('width'));
    var w = now + ((100 - now) * rnd) / 40;
    bar.setStyle('width: ' + w.toString() + '%');
    if(now < 100) setTimeout(add_random, (rnd * 1000));
  }
  setTimeout(add_random, (rnd * 1000))
}