Add GET fields from current URL to all hyperlinks on page

utm_tracking.js

<script type="text/javascript">
$(document).ready(function() {
    $('a').each(function() {
        var href = $(this).attr('href');
        if (href !== undefined) {
            if (href.indexOf('?') == -1) {
                var url = document.URL;
                var index = url.indexOf('?');
                if (index != -1) {
                    url = url.substring(index);
                    $(this).attr('href', href + url);
                }
            }
        }
    });
});
</script>