jquery find a div which does not have a span as the first child
<p>The number of divs is variable, but they all share a parent container:</p>

<pre><code>&lt;div&gt;
    &lt;span&gt;&lt;br/&gt;&lt;/span&gt;
    Lorem Ipsum
&lt;/div&gt;
&lt;div&gt;
    &lt;!-- need a span here --&gt;
    Lorem Ipsum
&lt;/div&gt;
&lt;div&gt;
    &lt;span&gt;&lt;br/&gt;&lt;/span&gt;
    Lorem Ipsum
&lt;/div&gt;
&lt;div&gt;
    &lt;!-- need a span here --&gt;
    Lorem Ipsum
&lt;/div&gt;
&lt;div&gt;
    &lt;span&gt;&lt;br/&gt;&lt;/span&gt;
    Lorem Ipsum
&lt;/div&gt;
</code></pre>

<p>How do I prepend a <code>span</code> tag to all the divs which don't have one. All the spans will be the same, they just have a line break so later on I can call <code>text()</code> on the parent and those will be converted into <code>\n</code>'s so the grouped content will show up nicely in an email where <code>enctype="text/plain"</code>.</p>
