onchange disable textarea php
<p>This is my form and i need to disable the textarea if the option city2 is selected and enable the textarea if the other options are selected.</p>

<pre><code>&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt;
&lt;html xmlns="http://www.w3.org/1999/xhtml"&gt;
&lt;head&gt;
&lt;meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /&gt;
&lt;title&gt;Untitled Document&lt;/title&gt;
&lt;script type="text/javascript"&gt;
var citySelect = document.getElementById('city'),
    descriptionTextarea = document.getElementById('description');

citySelect.addEventListener('change', function() {
    descriptionTextarea.disabled = citySelect.selectedIndex == 1;
}, false);
&lt;/script&gt;
&lt;/head&gt;
&lt;body&gt;
&lt;form method="post" name="areaform" id="areaform"&gt;
&lt;select name="city" id="city"&gt;
&lt;option value="city1"&gt;city1&lt;/option&gt;
&lt;option value="city2"&gt;city2&lt;/option&gt;
&lt;option value="city3"&gt;city3&lt;/option&gt;
&lt;/select&gt;&lt;br /&gt;
&lt;br /&gt;

&lt;textarea name="description" id="description" cols="" rows="" style="width:150px; height:50px;"&gt;&lt;/textarea&gt;
&lt;/form&gt;
&lt;/body&gt;
&lt;/html&gt;
</code></pre>

<p>How can i do that?</p>
