js 动态绑定解绑事件

function addEvent(obj, type, handle) {
    if (obj.addEventListener) {
        obj.addEventListener(type, handle);
    } else if (obj.attachEvent) {
        obj.attachEvent(‘on‘ + type, handle);
    }
}
function removeEvent(obj, type, handle) {
    if (obj.removeEventListener) {
        obj.removeEventListener(type, handle);
    } else if (obj.detachEvent) {
        obj.detachEvent(‘on‘ + type, handle);
    }
}