使用浏览器IE8时，获取Id，srcElement无效

Question

我正在尝试使用以下代码获取id，但它不适用于IE8。请帮我解决。

$.ShironekoTarot.prototype.result = function (event) {
    var targetElement = null;
    if (!event) event = window.event;
    if (event.target) {
        targetElement = event.target;
    } else if (event.srcElement) {
        targetElement = event.srcElement;
    }
    if ($(targetElement).is(this.options.cardNode) || !this.started || !this.controlable) {
        return;
    }
    this.controlable = false;
    var self = this,
        image = new Image();
    image.onload = function () {
        self._result(event.currentTarget);
    };
    var id = targetElement.id;
    this.options.cardResult = id;
    image.src = this.data.image;
};