What kind of arguments does this function take?
<pre><code>function countChars(elm) {  
    if (elm.nodeType == 3) { // TEXT_NODE  
        return elm.nodeValue.length;  
    }  
    var count = 0;  
    for (var i = 0, child; child = elm.childNodes[i]; i++) {  
        count += countChars(child);  
    }  
    return count;  
}  
</code></pre>

<p>I tried passing this function a string like <code>countChars("hello")</code>; but that didn't work.  What are examples of elements that I can pass?</p>
