Not choosing existing selection when randomising
<p>I have created a speech bubble that displays quotes that I store in lists. When I click the bubble it picks another quote from the list at random, but sometimes chooses the one it is already displaying. How would I prevent it from doing this?</p>

<pre><code>&lt;ul class="joke-list"&gt;
    &lt;li id="quotes"&gt;
        &lt;span style="color: rgb(0, 0, 0);"&gt;&lt;span style="font-size: medium;"&gt;Charles Darwin wanted to be a doctor but did not like the sight of blood.&lt;/span&gt;&lt;/span&gt;&lt;/li&gt;
    &lt;li id="quotes"&gt;
        &lt;span style="color: rgb(0, 0, 0);"&gt;&lt;span style="font-size: medium;"&gt;Charles Darwin was a member of the Gourmet Club. He ate lots of animals including armadillos, owls and tigers.&lt;/span&gt;&lt;/span&gt;&lt;/li&gt;
    &lt;li id="quotes"&gt;
        &lt;span style="color: rgb(0, 0, 0);"&gt;&lt;span style="font-size: medium;"&gt;For his 25th Birthday, Charles Darwin had a mountain named after him in Zimbabwe. &lt;/span&gt;&lt;/span&gt;&lt;/li&gt;
&lt;/ul&gt;
</code></pre>

<p>fiddle: <a href="http://jsfiddle.net/FsjkM/236/" rel="nofollow">http://jsfiddle.net/FsjkM/236/</a></p>
