What does this do: ($(":not(script)", destination).length == 0)
<p><strong>RESOLVED: 
The line destination.block(...) is the one causing the errors. I've forcing empty to equal true to avoid this. I think that the if (empty) statement is just picking between two different ways of displaying a busy message.</strong></p>

<p>I'm new to jQuery and have taken over maintaining an ASP.NET MVC 2 project from an ex-colleague. I'm struggling to understand what the following line of code is doing:</p>

<pre><code>var empty = ($(":not(script)", destination).length == 0);
</code></pre>

<p>This line causes and error in IE but not in Firefox. To be honest looking at the function below I don't think it's needed, but as my colleague did not believe in commenting his code. I need to understand the impact of changing the code. The context for the above is the following Javascript function:</p>

<pre><code>PRISMbase.LoadPartialEx = function(url, data, destination, successCallback, loadingMessage, appendNotOverwrite) {
    var empty = ($(":not(script)", destination).length == 0);
    var message = loadingMessage == null ? "Please wait" : loadingMessage;
    if (empty)
        destination.html(busy);
    else
        destination.block({ message: '&lt;h1 class="Progress"&gt;' + message + '&lt;/h1&gt;' });

    return $.ajax({
        data: data,
        dataType: "html", type: "GET", url: url,
        success: function(viewHtml) {
            var partial = $(viewHtml);
            if (!empty)
                destination.unblock();

            if(viewHtml != "")
            {
                if (appendNotOverwrite)
                    destination.append(partial);
                else
                    destination.html(partial);

                PRISMbase.InitialiseFormElements(destination);
            }
            else
                destination.empty();

            if (successCallback != null) successCallback(destination, partial);
        }
    });
}
</code></pre>

<p>In the above:</p>

<p>destination = a jQuery selector returning "#TabContent" (this is a div).</p>

<p>busy ='<code>&lt;img class="progress" src="/Content/OnyxProgressCircle.gif" /&gt;</code>';</p>

<p>Any help would be appreciated.</p>

<p>Thanks.</p>

<p>Alan</p>
