<script>
ijQuery(document).ready(function(){
// function that gets the url parameters
var getUrlParameter = function getUrlParameter(sParam) {
var sPageURL = decodeURIComponent(window.location.search.substring(1)),
sURLVariables = sPageURL.split('&'),
sParameterName,
i;
for (i = 0; i < sURLVariables.length; i++) {
sParameterName = sURLVariables[i].split('=');
if (sParameterName[0] === sParam) {
return sParameterName[1] === undefined ? true : sParameterName[1];
}
}
};
var utmSourcesFieldName = 'utm_source'; // the name of the field is the same as the url parameter
ijQuery("input[name='" + base64_encode(utmSourcesFieldName) + "']").attr('value', getUrlParameter(utmSourcesFieldName));
});
</script>