Elements to be have their default properties changed must to be placed after forms or the elements they are changing, ideally as a small box in the lower right corner. On the other hand code populating fields from cookies or parameters need to be placed before the form.

The following code snippet pre-populates a field. It needs to be placed before the form, retrieving the value before the field is displayed:

<script language="Javascript" src="/js/public/jquery-latest.min.js" type="text/javascript"></script>
<script src="/js/public/jQueryString-2.0.2-Min.js" type="text/javascript" ></script>
<script>
  // to set cookies.  Uses noConflict just in case
  var $jQ = jQuery.noConflict();
  var pEmail = $jQ.getQueryString({ ID: "Email" });

document.getElementById("Email").setAttribute("value", pEmail);

</script>

The next code resizes a text area. The Custom HTML box needs to be placed after the form:

<script src="/js/public/jquery-latest.min.js" type="text/javascript"></script>
<script type="text/javascript">
var $jQ = jQuery.noConflict();
$jQ(document).ready(function() {
$jQ('#MyFieldName').parents('li').css('margin-bottom','300px;');
});
</script>

<style type="text/css">
form.lpeRegForm textarea { width: 450px; }
</style>