debounce.js

function debounce (fn, delay) {
  var timer = -1;
  return function () {
    var that = this;
    var args = arguments;
    window.clearTimeout(timer);
    timer = window.setTimeout(function () {
      fn.apply(that, args);
    }, delay || 300);
  };
}

throttle.js

function throttle (fn, delay) {
  var on = true;
  return function () {
    if (!on) { return; }
    on = false;
    var that = this;
    var args = arguments;
    window.setTimeout(function () {
      fn.apply(that, args);
      on = true;
    }, delay || 300);
  };
}