You have so many forms in this page!
Keep only one <form> tag above the first input element
HTML Code:
<form method="post" action="comments.php">
<label for="name">Name:</label>
</div></td>
<td><div align="left">
<input name="name" type="text" id="name" size="50" maxlength="50" />
and close the form tag after the last element
HTML Code:
<input type="submit" name="submit" id="submit" value="Send" />
</form>
remove all other <form> and </form> tags
Going through these articles will help:
HTML Form Tutorial
and this
HTML form input examples