use getPosNumber() with JOptionPane
<p>I have been using Scanner to use this code, but I want to use JOptionPane to use this code, with getPosNumber. I tried compareTo(), but it's not working. Thanks!</p>

<pre><code>int height;
int length;

length = getPosNumber("What is the length of the rectangle?");
height = getPosNumber("What is the height of the rectangle?");
</code></pre>
