拿一个普通类div的src

Question

<div class="e1">
<p><img alt="" src="/images/site/pr1.png" /></p>
</div>
<div class="e1">
<p><img alt="" src="/images/site/pr2.png" /></p>

</div>
<div class="e1">
<h1> My new h1 </h1>
</div>

如何获取前两个div标签的img src元素的内容e1？