showHeader(''); function

// display all header stuff at beginning of page(s)
function showHeader($title) {
  define('LINK', 'http://' . $_SERVER['SERVER_NAME'] . '/');

  echo '
  <html lang="en">
    <head>
      <meta charset="utf-8">
      <meta http-equiv="X-UA-Compatible" content="IE=edge">
      <meta name="viewport" content="width=device-width, initial-scale=1">
      <meta name="google-signin-client_id" content="618381226281-f3ht6d47jl818rjmr0p3rh3idftoaka7.apps.googleusercontent.com">
      <link rel="stylesheet" href="<?php print(LINK); ?>includes/css.css" type="text/css" />
      <link rel="stylesheet" href="includes/media_queries.css" type="text/css" />
      <link href="https://fonts.googleapis.com/css?family=Roboto:100,300,400,500,700" rel="stylesheet">
      <link href="https://fonts.googleapis.com/css?family=Open+Sans" rel="stylesheet" type="text/css">
      <link href="https://fonts.googleapis.com/css?family=Oxygen:400,300,700" rel="stylesheet" type="text/css">
      <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.0/jquery.min.js"></script>
      <script src="includes/js.js"></script>
      <script src="https://www.google.com/recaptcha/api.js"></script>
      <script src="https://apis.google.com/js/platform.js" async defer></script>
      <title>'.$title.'</title>
    </head>

    <body>
    <header>
       <nav>
          <div class="navbar-left">
             <a href="index.php">
                <img src="http://i.imgur.com/4Cp2bQn.png" alt="heart[fx] logo" width="100px" />
             </a>
          </div>
  ';

          checkLogin();

  echo '
       <!-- closing tag for nav.navbar -->
       </nav>
    </header>
  ';
}