so, I have to define the variabel $POST['...'] not on the text field but on the php code directly???
No, the $POST and $GET arrays are automatically populated with the proper information. $POST and $_GET are populated typically with information from forms.
The only way to get information from a form to PHP is via the $POST and $GET arrays. There is no other option.
What you could do is make your SQL generic. Format it using the [man]sprintf[/man] guidelines. Your SQL (inside your txt file) would then look like:
added=>INSERT INTO forum VALUES ( '%s','%s','%s')
Then in your php code, you'd use it like:
$query2=sprintf($parseObj->added, mysql_real_escape_string($_POST['name']), mysql_real_escape_string($_POST['address']), mysql_real_escape_string($_POST['phone']));
I hope that helps explain some of it.