为了让用户单击抽认卡标题以打开和关闭抽认卡答案，我必须对以下代码进行哪些更改？
- 我无法让 toggle() 与淡入/淡出一起使用
- 以下版本不响应点击
代码：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script type="text/javascript"
src="http://www.google.com/jsapi"></script>
<script type="text/javascript">
google.load("jquery", "1.4.1");
google.setOnLoadCallback(function() {
$("div > div.question").click(function() {
if($(this).next().is(":hidden") {
$(this).next().fadeIn("slow");
} else {
$(this).next().fadeOut("slow");
}
});
});
</script>
<style>
div.flashcard {
margin: 0 10px 10px 0;
}
div.flashcard div.question {
background-color:#ddd;
width: 400px;
padding: 5px;
cursor: hand;
cursor: pointer;
}
div.flashcard div.answer {
background-color:#eee;
width: 400px;
padding: 5px;
display: none;
}
</style>
</head>
<body>
<div id="1" class="flashcard">
<div class="question">Who was Wagner?</div>
<div class="answer">German composer, conductor, theatre director and essayist, primarily known for his operas (or "music dramas", as they were later called). Unlike most other opera composers, Wagner wrote both the music and libretto for every one of his works.</div>
</div>
<div id="2" class="flashcard">
<div class="question">Who was Thalberg?</div>
<div class="answer">a composer and one of the most distinguished virtuoso pianists of the 19th century.</div>
</div>
</body>
</html>