why we create extra <tr> with display none

<?php 
if($_SERVER["REQUEST_METHOD"]=="POST"){
     $name = trim(filter_input(INPUT_POST,"name",FILTER_SANITIZE_STRING));
     $email = trim(filter_input(INPUT_POST,"email",FILTER_SANITIZE_EMAIL));
     $details = trim(filter_input(INPUT_POST,"details",FILTER_SANITIZE_SPECIAL_CHARS));
     echo "<pre>";
     if($name == "" || $email == "" || $details == ""){
          echo "Please fill input correctly";
          exit;
     }
     if($post["address"]!= ""){
      echo "Bad input";
      exit;
     }
     $mail_info = "";
     $mail_info .="Name : ". $name . "\n";
     $mail_info .= "Email : ".$email. "\n";
     $mail_info .= "Details : ".$details. "\n";
     echo $mail_info;
     echo "</pre>";

     //sending mail 
      header("location:suggest.php?status=thanks");
  }
$p_title = "Want to Suggest";
$sections = "suggest";
include("include/header.php");?>
<div class="section page">

  <?php if(isset($_GET["status"])&& $_GET["status"]=="thanks"){
     echo "<p>Thank You for sharing suggestions...</p>";
  } else { ?>
    <h1>Give your suggestions</h1>
  <p>If you think I missed anything here,send me mail</p>
    <form action="suggest.php" method="post">
        <table>
            <tr>
              <th><label for="name">Name</label></th>
              <td><input type="text" id="name" name="name"></td>
            </tr>
            <tr>
              <th><label for="email">Email</label></th>
              <td><input type="text" id="email" name="email"></td>
            </tr>
            <tr>
              <th><label for="details">Suggest Item Details</label></th>
              <td><textarea name="details" id="details" ></textarea></td>
            </tr>
             <tr style="display:none"> //why we using this with display:none
              <th><label for="address">Address</label></th>
              <td><input type="text" id="address" name="address"></td>
            </tr>

        </table>
        <input type="submit" value="send">
    </form>
</div>
<?php } ?>
<?php include("include/footer.php");?>