debounce.js

function debounce(fn, wait, immediate) {
  var timeout;
  return function() {
    var context = this, args = arguments;
    var later = function() {
	timeout = null;
	if (!immediate) fn.apply(context, args);
    };
    var callNow = immediate && !timeout;
    clearTimeout(timeout);
    timeout = setTimeout(later, wait);
    if (callNow) fn.apply(context, args);
  };
};