如何获取A？
复制代码代码如下:
<div>
<span>
A
<span>123</span>
</span>
</div>
<script type='text/javascript' src='./jquery-1.7.2.min.js'></script>
<script type='text/javascript'>
var a = $(".content")[0].firstChild.data;
function al(){
alert(a);
}
window.onload=al;
</script>