testing.html

<!DOCTYPE html>
<html>
    <head>
        <title>Testing</title>
        <style>
            *{
                font-family: Arial, Helvetica, sans-serif;
            }
        </style>
    </head>
    <body>
        <h1>The text below will change</h1>
        <p id="text"></p>
        <p id="text1"></p>
        <script>
            function getParameterByName(name, url = window.location.href) {
                name = name.replace(/[\[\]]/g, '\\$&');
                var regex = new RegExp('[?&]' + name + '(=([^&#]*)|&|#|$)'),
                    results = regex.exec(url);
                if (!results) return null;
                if (!results[2]) return '';
                return decodeURIComponent(results[2].replace(/\+/g, ' '));
            }
            document.getElementById("text").innerHTML = getParameterByName('foo'); // "lorem"
            document.getElementById("text1").innerHTML = getParameterByName('hello');
        </script>
    </body>
</html>