Untitled

  <body>
    <div class="header-container">
      <img src="images/information/banner1.png" alt="XXXX Banner" id="BannerIMG">
      <h1>Public Changelog</h1>
    </div>

    <div class="center-container">
      <form action="#" method="post">
        <select name="userDateOp" id="userDateOp">
          <option name="dateOp" value="today">today</option>
          <option name="dateOp" value="yesterday">yesterday</option><br>
          <input type="submit" value="submit">
      </form>
      <?php
        if(!isset($_POST['userDateOp'])) {
          $userOp = "example";
        }else{
          $userOp = $_POST['userDateOp'];
        }
        if(!isset($_POST['submit'])) {
          $changelog = fopen("p-changelog/$userOp.txt", 'r');
          $pageTxt = fread($changelog, 25000);
          echo nl2br($pageTxt);
        }
      ?>
    </div>
  </body>