<p>Say for instance I was writing a function that was designed to accept multiple argument types:</p>

<pre><code>var overloaded = function (arg) {
    if (is_dom_element(arg)) {
        // Code for DOM Element argument...
    }
};
</code></pre>

<p>What's the best way to implement <strong><code>is_dom_element</code></strong> so that it works in a cross-browser, fairly accurate way?</p>

Probably this one here:
```
```
node instanceof HTMLElement
```
```
That should work in most browsers.  Otherwise you have to duck-type it (eg.
```
typeof x.nodeType != 'undefined'
```
)