//绑定事件
    function addEventListener(element, type, fn) {
    //火狐 谷歌
    if (element.addEventListener) {
    element.addEventListener(type, fn, false);
    }
    //IE
    else if (element.attachEvent){
    element.attachEvent(‘on’ + type,fn);
    }
    //正常情况
    else {
    element[‘on’+type] = fn;
    }
    }
    //解绑事件
    function removeEventListener(element, type, fn) {
    //火狐 谷歌
    if (element.removeEventListener) {
    element.removeEventListener(type, fn, false);
    }
    //IE
    else if (element.detachEvent) {
    element.detachEvent(‘on’ + type, fn);
    }
    //正常情况
    else {
    element[‘on’+type] = null;
    }
    }