header.php

 <?php
 	session_start();
 ?>
 <!DOCTYPE html>
 <html>
 	<head>
 		<meta charset="utf-8">
 		<meta name="description" content="">
 		<meta name=viewport content="width=device-width, initial-scale=1">

 		<title></title>
 		<style>
			table .w3-button { display:none;}
			table tr:hover .w3-button { display:inline-block;}
			table, th, td {
            	width:400px;
            	height: 65px;
            	table-layout:fixed;
                overflow:hidden;
                word-wrap:break-word;
            }
		</style>
		<link rel="stylesheet" href="https://www.w3schools.com/w3css/4/w3.css">
		<link rel="stylesheet" href="https://www.w3schools.com/lib/w3-theme-black.css">
		<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto">
		<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
 	</head>
 	<body>
		<?php
			if (isset($_SESSION['userId'])) {
			echo '<div class="w3-top">
  					<div class="w3-bar w3-theme w3-top w3-left-align w3-large">

  						<a href="mylisttoday.php" class="w3-bar-item w3-button w3-hide-small w3-hover-white">My List Today</a>

					    <a href="addlist.php" class="w3-bar-item w3-button w3-hide-small w3-hover-white">Add List</a>

					    <a href="notes.php" class="w3-bar-item w3-button w3-hide-small w3-hover-white">Notes</a>

					    <form action="includes/logout.inc.php" method="post">

								  <button class="w3-button w3-black" class="w3-button w3-black" type="submit" name="logout-submit"><b><i>Logout</i></b>
								  </button>
						</form>
					</div>
				  </div>';
			}
			else {

				echo '<div class="w3-main">
						<div class="w3-row w3-padding-64">
						  <div class="w3-twothird w3-container">
						  	<h1><b>You are logged out</b></h1>
						  	<h3>Login below, or register an account</h3><br>
							<form action="includes/login.inc.php" method="post">
									<input type="email" name="mailuid" placeholder="Email">

						    <input type="password" name="pwd" placeholder="Password"><br>

							<button class="w3-button w3-blue" type="submit" name="login-submit">Login</button>
							<a href="signup.php">Register</a></form>
						  </div>
						</div>
					  </div>';

			}
		?>

	</body>
 </html>