.attr('checked','checked') does not work
<p>I am trying to check radio. Neither the following works:</p>

<p>[edit]</p>

<pre><code>$('selector').attr('checked','checked');
$('selector').attr('checked',true);
</code></pre>

<p>The two alert() in the following code show "1" and "a", respectively. My expectation is the second alert() showing "b".</p>

<p>Opera does check the second radio box in its browser, but its element inspector, dragonfly, shows that the DOM is not changed.</p>

<p>[end edit]</p>

<p>I had read the FAQ before I posted this question:</p>

<p><a href="http://docs.jquery.com/Frequently_Asked_Questions#How_do_I_check.2Funcheck_a_checkbox_input_or_radio_button.3F" rel="nofollow">http://docs.jquery.com/Frequently_Asked_Questions#How_do_I_check.2Funcheck_a_checkbox_input_or_radio_button.3F</a></p>

<p>Helps will be much appreciated!</p>

<p>TIA</p>

<p>The xhtml page and code follows:</p>

<pre><code>&lt;!DOCTYPE html 
     PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
     "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"&gt;
&lt;html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"&gt;
&lt;head&gt;
&lt;meta http-equiv="Content-Type" content="text/html; charset=utf-8"/&gt;
&lt;title&gt;Weird Behavior&lt;/title&gt;
&lt;script type="text/javascript" src="scripts/jquery.js"/&gt;
&lt;script type="text/javascript"&gt;
function clickme(){
    alert($('input[name="myname"][value="b"]').length);
    $('input[name="myname"][value="b"]').attr('checked','checked');
    $('#b').attr('checked',true);
    alert($('input[name="myname"][checked]').val());
};
&lt;/script&gt;
&lt;/head&gt;
&lt;body&gt;
    &lt;form action=""&gt;
        &lt;fieldset&gt;
            &lt;legend&gt;Why check is not switched?&lt;/legend&gt;
            &lt;input type="radio" name="myname" value="a" id="a" checked="checked"/&gt;A
            &lt;input type="radio" name="myname" value="b" id="b"/&gt;B
        &lt;/fieldset&gt;
    &lt;/form&gt;
    &lt;p&gt;
    &lt;button type="button" onclick="clickme()"&gt;click me&lt;/button&gt;
    &lt;/p&gt;
&lt;/body&gt;
&lt;/html&gt;
</code></pre>
