JS: Fill Out UTM Values into an infusionsoft Form

script.js

<script>
    $(function(){
        setFormValue('inf_custom_UTMCampaign', getQueryVal('utm_campaign'));
        setFormValue('inf_custom_UTMMedium', getQueryVal('utm_medium'));
        setFormValue('inf_custom_UTMSource', getQueryVal('utm_source'));
        setFormValue('inf_custom_UTMContent', getQueryVal('utm_content'));
        setFormValue('inf_custom_UTMTerm', getQueryVal('utm_term'));
        setFormValue('inf_custom_UTMReferurl',document.referrer);

        function getQueryVal(name) {
          name = name.replace(/[\[]/, "\\[").replace(/[\]]/, "\\]");
          var regex = new RegExp("[\\?&]" + name + "=([^&#]*)"),
          results = regex.exec(location.search);
          return results === null ? "" : decodeURIComponent(results[1].replace(/\+/g, " "));
        }

        function setFormValue(item, value){
            if(value !== undefined || value !== null){
                $('[name="' + item + '"]').val( value );
            }
        }
    });
</script>