form.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="author" content="Brandon Monroe">
    <title>My first form</title>
    <script>
        function generateEmail(form){
            document.getElementById("email").innerHTML = form.elements["first"].value + "." + form.elements["last"].value + "@atu.edu";
            form.reset();
            
        }
    </script>
</head>
<body>
    <form>
        First Name: <input type="text" id="first" placeholder="Enter your first name" size="15" autofocus> <br>
        Last Name: <input type="text" id="last" placeholder="Enter your last name" size="15"> <br><br> 
        
        <input type="button" value="Generate Email" onclick="generateEmail(this.form);">

        <p id="email">

        </p>
    </form>
    
</body>
</html>