Yes i do, but i am not writing it for you or showing you one, i doubt you wrote your current code if you can't make a form using $_POST, to post to it's self.
Please look at some web tutorials on tizag and w3schools and learn php form interaction.
If you want it wrote for you create a post in the freelancing section.
Post the form to the same page it's on, then do all the form processing there and the error checking, then you can show errors without using $_GET at all.
I don't think you can do it like that, i don't think you can include files and use $_GET or $_POST in them.
Why not have an if statement instead in the main page?
OK, then sorry but your code is to untidy (makes it hard to read) and there are to many if statements in your code.
My advice would be to have the form self post and then present any error messages on that page.
Then it must be being directed there, check your code for any headers etc. that might be doing this, check all the pages that the form can possibly go to.
my advice to you is to learn what you are doing and don't just rely on dreamweaver, go to sites like tizag.com and w3schools.com to learn about php and mysql
I would use post, i prefer it to using get for login's.
Also , i assume you are using a HTML generator
<FORM NAME="login" METHOD="post" ACTION="login.php?mode=1">
Should be
<form name="login" method="post" action="login.php?mode=1">
We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.