Function addEvent

src/ResizeSensor.js:284–290

(el, name, cb)

            };

            var addEvent = function(el, name, cb) {
                if (el.attachEvent) {
                    el.attachEvent('on' + name, cb);
                } else {
                    el.addEventListener(name, cb);
                }
            };

            addEvent(expand, 'scroll', onScroll);
            addEvent(shrink, 'scroll', onScroll);