Understanding this javascript jquery function in function snippet
<p>This is partly a jquery question, but most javascript.  I just don't know javascript well enough to understand this code:</p>

<pre><code>1 (function () {
2            $(function () {
3                //Global ajax progress dialog box
4                //Simply run $("#ajax-progress-dialog").dialog("open"); script before the ajax post and
5                //$("#ajax-progress-dialog").dialog("close"); on the ajax post complate
6                $("#ajax-progress-dialog").dialog({
7                    autoOpen: false,
8                    draggable: false,
9                    modal: true,
10                    height: 80,
11                    resizable: false,
12                    title: "Processing, please wait...",
13                    closeOnEscape: false,
14                    open: function () { $(".ui-dialog-titlebar-close").hide(); } // Hide close button
15                });
16            });
17        })(); 
</code></pre>

<p>I understand lines 3-15. In fact, I think I understand lines 2 through 16:  this is creating an anonymous function and wrapping it as a jquery object, right?  Not sure why it needs to be wrapped, but more importantly, I especially don't understand lines 1: opens with "(function" and 17: closes with ")()". What's that about?</p>

<p>BTW, for completeness, note that this is invoked as follows:</p>

<p>$("#ajax-progress-dialog").dialog("open");</p>

<p>Credit: this example comes from  <a href="http://www.tugberkugurlu.com/archive/working-with-jquery-ajax-api-on-asp-net-mvc-3-0-power-of-json-jquery-and-asp-net-mvc-partial-views" rel="nofollow">tugberkugurlu</a></p>
