/**

 * 简易的事件添加方法

 */

define(function(require, exports, module) {

    exports.addEvent = (function(window, undefined) {

        var _eventCompat = function(event) {

            var type = event.type;

            if (type == 'DOMMouseScroll' || type == 'mousewheel') {

                event.delta = (event.wheelDelta) ? event.wheelDelta / 120 : -(event.detail || 0) / 3;

            }

            //alert(event.delta);

            if (event.srcElement && !event.target) {

                event.target = event.srcElement;

            }

            if (!event.preventDefault && event.returnValue !== undefined) {

                event.preventDefault = function() {

                    event.returnValue = false;

                };

            }

            /*

               ......其他一些兼容性处理 */

            return event;

        };

        if (window.addEventListener) {

            return function(el, type, fn, capture) {

                if (type === "mousewheel" && document.mozFullScreen !== undefined) {

                    type = "DOMMouseScroll";

                }

                el.addEventListener(type, function(event) {

                    fn.call(this, _eventCompat(event));

                }, capture || false);

            }

        } else if (window.attachEvent) {

            return function(el, type, fn, capture) {

                el.attachEvent("on" + type, function(event) {

                    event = event || window.event;

                    fn.call(el, _eventCompat(event));

                });

            }

        }

        return function() {};

    })(window);

});

addEvent(dom, "mousewheel", function(event) {

    if (event.delta < 0) { alert("鼠标向上滚了！"); }

});