Javascript's JOptionPane equivalent?
<p>I've got an alert box but I'd like there to be an <code>Okay</code> and then a <code>Canel</code> button like a JOptionPane in Java. </p>

<p>Basically it'd work like this...</p>

<pre><code>"Message"
 if okay then 
 this();
 else 
 that();
</code></pre>

<p>Does Javascript have this built in?</p>
