事件监听

window.onload = function() {

var oneClick = function() {

alert("第一个事件");

};

var twoClick = function() {

alert("第二个事件");

};

var threeClick = function() {

alert("第三个事件");

}

var btn = document.getElementById("event");

btn.addEventListener("click", oneClick);

btn.addEventListener("click", twoClick);

btn.addEventListener("click", threeClick);

btn.removeEventListener("click", threeClick);

}