I found this wonderful script on the Internet that after a few subtle changes does a nice effort of moving from one list box to another.

http://www.plus2net.com/javascript_t...list-move.html

However, I need to pass this back to the server as an array and it simply doesn't work. Can anyone help?

It will be submitted to the server as a comma separated string. Your server side code will have to put it into an array.

However, when I dump the post values, the listbox variable is not listed.

I found this link:
http://onlinetools.org/tricks/using_multiple_select.php

<select name="test[]" multiple="multiple">
	<option value="one">one</option>
	<option value="two">two</option>
	<option value="three">three</option>
	<option value="four">four</option>
	<option value="five">five</option>
</select>

I notice that name=test[] rather than name=test. What do I need to do to the Javascript so that it accepts the name as test[] rather than test?

http://www.webbysoft.com/babelkit/doc/bk_select.html