JS debounce

gistfile1.txt

function debounce(func, delay) {
  var alreadyScheduled;
  var lastTimer;
  
  return function() {

    if (alreadyScheduled) {
      clearTimeout(lastTimer);
    }

    alreadyScheduled = true;

    lastTimer = setTimeout(function() {
      func();
      alreadyScheduled = false;
    }, delay);
  }
}