What does the question mark mean in this function?
<p>Here's the documentation for this plugin (There's only two functions.)
<a href="http://tkyk.github.com/jquery-history-plugin/#documentation" rel="nofollow">http://tkyk.github.com/jquery-history-plugin/#documentation</a></p>

<pre><code>$(document).ready(function() {
    function load(num) {
        $('#content').load(num +".html");
    }

    $.history.init(function(url) {
        load(url == "" ? "1" : url);
    });

    $('#ajax-links a').live('click', function(e) {
        var url = $(this).attr('href');
        url = url.replace(/^.*#/, '');
        $.history.load(url);
        return false;
    });
});
</code></pre>

<p>Here's the html:</p>

<pre><code>&lt;body&gt;
  &lt;h1&gt;jQuery History Plugin Ajax Sample&lt;/h1&gt;
  &lt;div id="ajax-links"&gt;
    &lt;ul&gt;
      &lt;li&gt;&lt;a href="#1"&gt;load 1.html&lt;/a&gt;&lt;/li&gt;
      &lt;li&gt;&lt;a href="#2"&gt;load 2.html&lt;/a&gt;&lt;/li&gt;
      &lt;li&gt;&lt;a href="#3"&gt;load 3.html&lt;/a&gt;&lt;/li&gt;
    &lt;/ul&gt;
    &lt;div id="content"&gt;&lt;/div&gt;
    &lt;hr /&gt;
  &lt;/div&gt;
  &lt;p&gt;[&lt;a href="../"&gt;All samples&lt;/a&gt;] [&lt;a href="http://github.com/tkyk/jquery-history-plugin"&gt;Project home&lt;/a&gt;]&lt;/p&gt;
&lt;/body&gt;
</code></pre>
