next.html

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title>Next Page</title>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
    <script type="text/javascript">
        $(document).ready(function(){
            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 first = getUrlParameter('firstname');
            var last = getUrlParameter('lastname');
            $('.results').html(first + last)
         });
    </script>
</head>
<body>
<div class="results"></div>
</body>
</html>