SO fiddle

Test Fiddle mainly for SO Questions

by Nick Craver

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/overcast/jquery-ui.css">
<script src="http://github.com/vitch/jquery-methods/raw/master/date.js"></script>
<script src="http://www.kelvinluck.com/assets/jquery/datePicker/v2/demo/scripts/jquery.datePicker.js"></script>
<link rel="stylesheet" href="http://www.kelvinluck.com/assets/jquery/datePicker/v2/demo/styles/datePicker.css">
<select id="ctl00_dd1" name="ctl00$dd1">
<option value="HANW"></option>
    <option value="HEYD"></option></select>

<div style="display: none;"> <div class="evenprop"><h3 class="locname">Hanworth</h3><span class="locid" style="display:none">HANW</span></div> <div class="evenprop"><h3 class="locname">Heydon</h3><span class="locid" style="display:none">HEYD</span></div> </div>

JavaScript

$("div.evenprop .locid").each(function() { 
  $("#ctl00_dd1 option[value='" + $(this).text() + "']").text($(this).prev().text()); 
});