index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Chatella</title>
    <link rel='stylesheet' href='/style.css' type='text/css'/>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.1.1/socket.io.js"></script>
    <script src="/chat.js"></script>
    <script src="https://www.gstatic.com/firebasejs/6.4.1/firebase-auth.js"></script>.
</head>
<body>
<div class="onlineUsersContainer">
    <div class="userInfo">Welcome <label id="myName">Guest</label> !!</div>
    <div>
        <ul id="onlineUsers"></ul>
    </div>
</div>
<div class="chatContainer">
    <ul id="messages"></ul>
    <span id="notifyTyping"></span>
    <form id="form" action="" onsubmit="return submitfunction();">
        <input type="hidden" id="user" value=""/><input id="m" autocomplete="off" onkeydown="notifyTyping();"
                                                        placeholder="Type your message here.."/><input type="submit"
                                                                                                      id="button"
                                                                                                      value="Send"/>
    </form>
</div>
</body>
</html>