How to add A text area located outside a form (but still a part of the form)

Textarea Example.

index.html

Example: HTML

 <form action="/action_page.php" id="usrform">
  Name: <input type="text" name="usrname">
  <input type="submit">
</form>

<textarea name="comment" form="usrform">Enter text here...</textarea>

Output should be:

Type:	html
Category:	Web Tutorial
Sub Category:	HTML Attribute
Uploaded by:	Admin