Throttle events

throttle.js

 function throttle(callback, throttleTimeout, throttleTicks) {
    throttleTimeout = throttleTimeout || 50;
    throttleTicks   = throttleTicks   || 20;

    var tick = 0,
        timeout;

    return function() {
      var args = arguments;

      tick = (tick + 1) % throttleTicks;

      clearTimeout(timeout);

      if (tick === 0) {
        callback.apply(null, arguments);
      } else {
        timeout = setTimeout(function() {
          callback.apply(null, args);
        }, throttleTimeout);
      }
    };
  }