如何从我的所有网站启用向html页面发送评论，并且每次只显示当前页面的一部分？

I have a website and I want to make it possible to send comments anywhere on the site through one php page. The problem I wrote the following code on PHP and it keeps all responses only into one html page. How can I keep all responses into one html page show per page just the reactions belonging to the same page?

here my php code:

$handle = fopen("comments.html","a");
fwrite ($handle,"<b>" . "<h2 style=" . "\"color:blue;\"" . ">" .  $_POST["name"] . "</b></h2>"  . $_POST["comment"] . "</br><hr>" ); 
fclose ($handle);

and here my html code, I want him to see only the comments written on this page.

<h2 style="color:green;">comments:</h2>
<p><span class="error" style="color:red;">* must</span></p>

<form method="post" action="comments/comments.php">  

 <span class="error" style="color:red;">* <?php echo $nameErr;?></span>
  name:
 <input type="text" name="name"> 
 
  <br><br>
   comment:
  <textarea name="comment" rows="5" cols="40"></textarea>
  <br>
  <input type="submit" name="submit" value="send:">  
  <input type="reset"  value="clear:"
  <hr>
</form>

<?php
include "comments/comments.html";
?>

tnx!

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