title: Sorting a Drop-down (value) list by second field that's not displayed
body: <p>How can I have a drop-down (value) list sorted by a second field (<code>sortId</code>) <strong>without showing</strong> that field? (I also want to include a &quot;separator line&quot;.)</p>
  <p>My current solution uses a second field of whitespaces to sort, but this leads to unfortunate behaviour.</p>
  <h3>Problem:</h3>
  <p>As the list needs to be dynamic (i.e. read from a table) I cannot use a Custom Value List.<br />
  The list should look like this:</p>
  <pre><code>zzz (sortId = 1)
  aaa (sortId = 2)
  bbb (sortId = 3)
  -------------------     (Does maybe also have to be defined with a sortId..)
  uuu (sortId = 4)
  lll (sortId = 5)
  rrr (sortId = 6)
  </code></pre>
  <p>But the <code>sortId</code> should not be displayed in the drop-down list.</p>
  <h3>What I tried:</h3>
  <p>Since drop-down lists get sorted alphabetically I found out that there is <a href="http://forums.filemaker.com/posts/cbe27249a0" rel="nofollow noreferrer">this trick</a> with using a second field which
  contains &quot;whitespaces&quot; as sorting order. With a script/command:</p>
  <pre><code>Substitute(10^sortId - 1, &quot;9&quot;, &quot; &quot;) 
  </code></pre>
  <p>I am able to convert <code>sortId</code> into the correct amount of whitespaces. The sorting then works...</p>
  <p><strong>However</strong>, whitespaces are still shown in the Drop-down list and because we have maybe around 100 items in the value list it expands the drop-down to the right.</p>
  <p>Another problem is that we need to use the &quot;-&quot; as separator line, but with this approach the &quot;-&quot; does not get replaced by the separator line, because the blank whitespaces are still filled behind it so its &quot;-     &quot; and this
  does not get replaced by the separator line.</p>