title: DateTimePicker wont update the value field onChange or onSelect
body: <p>I am trying to update the value of an input when i change the selected date. 
  This is my html code for the input. </p>
  
  <pre><code>&lt;input type="text" name="completed_date" id="completed_date" size="12" class="completed_date fielddate" value="&lt;?php echo date("d/m/Y",strtotime("now"))?&gt;" readonly /&gt;
  </code></pre>
  
  <p>This is my jquery onSelect function</p>
  
  <pre><code> $(document).ready(function() {
    $('.completed_date').datetimepicker({
     timepicker: false,
     format: 'd/m/Y',
      onSelect: function() {
       var date = $(this).val();
       $('#completed_date').val(date);
      }
    });
   });
  </code></pre>
  
  <p>This code has no effect on my input field but if i change the last line to </p>
  
  <pre><code>$('#completed_date').text(date);
  </code></pre>
  
  <p>then it adds the new selected date to the end of the html line.</p>
  
  <p><code>&lt;input type="text" name="completed_date" id="completed_date" size="12" class="completed_date fielddate" value="&lt;?php echo date("d/m/Y",strtotime("now"))?&gt;" readonly /&gt;</code> <strong><em>Adds the date here</em></strong></p>
  
  <p>The code in the value field currently shows today's date by default but should be updated onSelect.</p>
  
  <p>I have read the documentation but cant seem to find what im missing.
  Any help will be greatly appreciated.</p>
  
  <p>It updates visually in the field but the actual value in the input doesn't change so when i click save it always sends today's date instead of the selected date</p>