Login on same page? Redirections

[geraldpolar]

So I am having this problem on my page its my login.

 

Well its actually being included on my mainfile(index.php)

 

<div id="login_content_one"><div id="login_one"><?php include('home.php') ?></div></div>

 

And this is my home.php code

 

echo "<form action='login.php' method='POST'>";

 

As it goes from home.php>login.php it changes to a different page, how can i maintain the trapping message like ("No username") on the same  page?

 

This is a good example, gerald.hengeraldtrading.com < check the login it goes on another page.

[landysaccount]

In login.php check if username is set:

 

if( isset($_REQUEST['username'] ) && $_REQUEST['username'] == '' ){

  echo "No username";

}

[geraldpolar]

its still going out on another page

 

Is there anyway to properly include somefiles? like login area on a webpage