jQuery generated text on click upon if statement, remains after if is false
<p>I've got a form with some radio buttons in it. When a link is clicked, the value of the selected radio button is passed to a text field. If the value is '0', the text 'Not required' is given to a div, overwriting where the output would have been if it wasn't '0'.</p>

<p>When you click the '0' radio button then click the link, it works as it should. The problem is that if you change to a different radio button then click the link again, the text remains. What I want to happen is for that message to only appear when the '0' is selected and for it to be removed if a non-'0' is chosen.</p>

<p>I've set it up on <a href="http://jsfiddle.net/thewebdes/gnW2c/" rel="nofollow">http://jsfiddle.net/thewebdes/gnW2c/</a> so you can see what I mean. In the actual project, the 'Not required' text will overwrite anything else that would have appeared so clearing the html using jquery at the beginning of the click function is a no-go.</p>

<p>HTML</p>

<pre><code>&lt;form action="#" method="post"&gt;
    &lt;label for="item1_qty1"&gt;0&lt;/label&gt;
    &lt;input type="radio" id="item1_qty1" name="item1_qty" value="0"&gt;
    &lt;br&gt;
    &lt;label for="item1_qty1"&gt;100&lt;/label&gt;
    &lt;input type="radio" id="item1_qty1" name="item1_qty" value="100"&gt;
    &lt;br&gt;
    &lt;label for="item1_qty1"&gt;250&lt;/label&gt;
    &lt;input type="radio" id="item1_qty1" name="item1_qty" value="250"&gt;
    &lt;br&gt;
    &lt;label for="item1_qty1"&gt;500&lt;/label&gt;
    &lt;input type="radio" id="item1_qty1" name="item1_qty" value="500"&gt;

    &lt;a href="javascript:;" class="gen_output"&gt;Get Value&lt;/a&gt;

    &lt;div class="output"&gt;
        &lt;label for="item1_qty_output"&gt;Item 1 Output&lt;/label&gt;
        &lt;input type="text" id="item1_qty_output"&gt;
    &lt;/div&gt;
&lt;/form&gt;
</code></pre>

<p>JS</p>

<pre><code>$('.gen_output').click(function() {
    $('#item1_qty_output').val($('input:radio:checked').val());
    if ($('input:radio:checked').val() == '0') {
        $('.output').html('Not required')
    }
});
</code></pre>
