Retrieve values from a pop up window to the parent window
<p>I have a pop up window that contains some selections. Once the user selects options, the selected options need to be displayed in the main window. The main window doesn't need to be refreshed when options are selected from the pop up window. I'm using javascript for this, but I cannot figure out how to access the <code>checkbox</code> item of the pop up window from the main window.</p>

<p>Example:</p>

<pre><code>&lt;input type="checkbox" name="vehicle[]" value="Bike" /&gt; 
&lt;input type="checkbox" name="vehicle[]" value="car" /&gt;

var chbox = document.getElementById("vehicle[]").value; 
</code></pre>

<p>But this doesn't work.</p>
