Can't hide labels; JQuery
<p>What am I doing wrong ? -<em>_</em>-</p>

<p>Alert displays, but that's it.</p>

<pre><code>    &lt;asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeaderContent"&gt;

        &lt;script type="text/javascript"&gt;
            if (navigator.userAgent.match(/Android/i)) {
            }
            else if (navigator.userAgent.match(/webOS/i)) {
            }
            else if (navigator.userAgent.match(/iPhone/i)) {
            }
            else if (navigator.userAgent.match(/iPod/i)) {
            }
            else {
                alert("I'm a PC");
                $('#Label2').hide();
                $('#Label3').hide();
                $('#Label4').hide();
            }
       &lt;/script&gt;

&lt;/asp:Content&gt;

(...)

&lt;div data-role="content"&gt;

            (...)

            &lt;label id="Label1"&gt;
                Explanation to save it and/or bookmark (PC / Others)
            &lt;/label&gt;
            &lt;label id="Label2"&gt;
                Explanation to save it and/or bookmark (iOS)
            &lt;/label&gt;
            &lt;label id="Label3"&gt;
                Explanation to save it and/or bookmark (Android)
            &lt;/label&gt;
            &lt;label id="Label4"&gt;
                Explanation to save it and/or bookmark (BlackBerry)
            &lt;/label&gt;
        &lt;/div&gt;
</code></pre>
