Watch function
var watch = function (eventType, element, callback, time) {
var handler = false;
//set a default time value
time = typeof time !== 'undefined' ? time : 2000;
var watcher = function (evt) {
clearTimeout(handler)
handler = setTimeout(callback.bind(element), time);
}
element.addEventListener(eventType, watcher);
};
//Usage
var text = document.getElementById('test');
watch('keyup', text, function () {
console.log(this.value);
});