Convert CSS3 transition duration string to milliseconds

gistfile1.js

var transitionDurationToMilliseconds = function(duration) {
  var pieces = duration.match(/^([\d\.]+)(\w+)$/),
    time, unit, multiplier;

  if (pieces.length <= 1) {
    return duration;
  }

  time = pieces[1];
  unit = pieces[2];

  switch(unit) {
    case 'ms': multiplier = 1; break;
    case 's': multiplier = 1000; break;
  }

  return time * multiplier;
};