通过电子邮件重定向联系表单

Question

我使用电子邮件重定向创建了简单的联系表单，  但是当我刷新页面时，它总是在页面顶部显示几个通知：

  

注意：未定义的索引：......在线...

提交表格工作正常，我怎么能摆脱这个通知？

这是代码：

<?php
/* ========================================================
   1. | FORM VALIDATION
=========================================================== */
//response generation function
$response = "";
//function to generate response
function contact_form_response($type, $message) {
global $response;

if($type == "success") $response = "<div class='success'>{$message}</div>";
else $response = "<div class='error'>{$message}</div>";
}

/* ========================================================
   2. | Errors
=========================================================== */
  //response messages
  $not_human       = "Not-Human - wrong Number";
  $missing_content = "Missing  content";
  $email_invalid   = "Email - wrong adress";
  $message_unsent  = "Message Unsent - Try again";
  $message_sent    = "Thanks for Contact!" . "</br>" ."See you soon :)";

  //Min/Max messages
  $to_short_name      = "Name: To short"; 
  $to_long_name       = "Name: To Long";   

  $to_short_mess      = "Message: To short"; 
  $to_long_mess       = "Message: To Long"; 

  $no_number     = "Name/Message: Error - Only numbers, huh?";
  $no_letter     = "Only Numbers"; 
  $no_about     = "Select Subject"; 

  //user posted variables
  $name = $_POST['message_name'];
  $email = $_POST['message_email'];
  $about = stripslashes($_POST['about']);

  $message = $_POST['message_text'];
  $human = $_POST['message_human'];


/* ========================================================
   3. | E-MAIL Adress 
=========================================================== */
$to ='your@email.com';

// Change the Email Addresses below to email Id where you want to get your emails.
// Reply Email Address where you want to set reply to email ID

$uploadpath='/scripts/test/';

$save_path ='http://'.$_SERVER['SERVER_NAME'].$uploadpath;  // do not change this

// Change E-mail Adress, depend on chosen Subject from Dropdown List
switch ($about) {
case "Test": // Change to Value from Dropdown List
$to='test@test.com'; // change to different e-mail
break;


}// end switch



/* ========================================================
   4. | SEND E-MAIL
=========================================================== */
$subject = "Page: ".get_bloginfo('name') ." | Author: " . $_POST['message_name'] . 
  " | Subject: " . $_POST['about'];

  $headers="From: $email <br>";
  $headers.="Name: $name <br>";
  $headers.="Email: $email <br>";
  $headers.="About: $about <br>";
  $headers.="Message: $message <br>";


  if(!$human == 0){
    if($human != 6) contact_form_response("error", $not_human); //not human!
    else {

      //validate email
      if(!filter_var($email, FILTER_VALIDATE_EMAIL))
        contact_form_response("error", $email_invalid);
      else //email is valid
      {
        //validate presence of name and message
        if(empty($name) || empty($message)){
          contact_form_response("error", $missing_content);
        }   

        // Checks About Field
        if(!$about){
        contact_form_response("error", $no_about );
                    }   

        // To Short Name
        else if(strlen($name) < 6){
        contact_form_response("error", $to_short_name );

        } // To Long Name
        else if(strlen($name) > 50) {
        contact_form_response("error", $to_long_name ); 
        }

        // Numeric Name 
        else if(is_numeric($name) || (is_numeric($message)) ) {
        contact_form_response("error", $no_number );    
        }

        // To Short Message
        else if(strlen($message) < 10){
        contact_form_response("error", $to_short_mess );

        } // To Long Message
        else if(strlen($message) > 2000) {
        contact_form_response("error", $to_long_mess ); 
        }


        else //ready to go!
        {
          $sent = wp_mail($to, $subject, strip_tags($message), $headers);
          if($sent) contact_form_response("success", $message_sent); //message sent!
          else contact_form_response("error", $message_unsent); //message wasn't sent
        }
      }
    }
  }
  else if ($_POST['submitted']) contact_form_response("error", $missing_content);


?>

<?php
/*
 * Template Name: Contact Us
 *
 */

get_header(); ?>

<div id="primary" class="content-area">
<main id="main" class="site-main" role="main">


<form id="contact-form"action="<?php the_permalink(); ?>" method="post">
<h2>Contact Form</h2>
<?php echo $response; ?>

<label for="name">Name:
<input type="text" placeholder="John Smith" name="message_name" 
value="
<?php if(isset($_POST['message_name'])) echo $_POST['message_name'];?>">
</label>



<label for="message_email">Email:
<input type="text" placeholder="your@email.com" name="message_email" 
value="
<?php if(isset($_POST['message_email'])) echo $_POST['message_email'];?>"></label>

<select name="about" class="about">
<option value="">▲ Choose Subject ▼</option>


<option value="Test">Test</option>

</select>

<label for="message_text">Message:
<textarea type="text" name="message_text">
<?php if(isset($_POST['message_text'])) echo $_POST['message_text'];?></textarea></label>

<label for="message_human">Are you Human?
<input type="text" placeholder="Write Number" name="message_human">3 + 3 = ?</label>

<input type="hidden" name="submitted" value="1">
<input type="submit" value="Send">
</form>


</main><!-- #main -->
</div><!-- #primary -->

<?php get_sidebar(); ?>
<?php get_footer(); ?>