切换隐藏：无法在HTML / CSS中与JS一起使用吗？

Question

http://jsfiddle.net/bDQt7/1/

Toggle hidden : unhidden doesn't work, and I can't figure out why?

html

<a href="javascript:unhide('menu');">Toggle</a>

<div id="top">
    <div id="menu" class="hidden">
        hello
    </div>
</div>

css

.hidden {
    display: none;
}
.unhidden {
    display: block;
}

JS

function unhide(divID) {
    var item = document.getElementById(divID);
    if (item) {
        item.className = (item.className == 'hidden') ? 'unhidden' : 'hidden';
    }
}

Answer 1

Try

Wrap code in body or head below your html.

Working fidde