Can't change css when using click in jquery
<p>I have a small demo:</p>

<pre><code>&lt;div class="box_content_height"&gt;
    &lt;strong&gt;Height: &lt;/strong&gt;
    &lt;input type="text" name="height" id="height" value="300" /&gt;px
    &lt;input type="submit" class="submit_advance" value="submit" /&gt;    
&lt;/div&gt;
</code></pre>

<p>And javascript</p>

<pre><code>$('.submit_advance').click(function() {
        var height_css = $('#height').val();
        $('ul.nav-scroll').css('max-height', height_css+'px');
});
</code></pre>

<p>When I type input = 500 is result css no change 500
How to result is </p>

<pre><code>.ul.nav-scroll {
    max-height: valueofinput+px
}
</code></pre>
