PHP - PHP No funciona al igualar 2 palabras identicas

<form action="<?php echo $_SERVER['login/PHP_SELF']; ?>" method="post">

<?

		$pfile = fopen("includes/userpwd.txt","r");

		rewind($pfile);

		while (!feof($pfile)) {

			while ($line = fgets($pfile)){

			    $tmp = explode('\n', $line);

		 	    $tmp2 = explode(':', $tmp[0]);

			   echo "<label>".trim($tmp2[0]).' <input name="username" value="'.trim($tmp2[0]).'" type="radio"></label<br>';

			}

		}

		fclose($pfile);

?>

<input value="Reiniciar" name="submitBtn" type="submit">

</form>

if (isset($_POST['submitBtn'])){

		echo $username;

		$username  = isset($_POST['username']) ? $_POST['username'] : '';

		// Try to register the user

		$jh = new loginjh();

		$error = $jh->formatUser($username);

	}

function formatUser($username)

	{

		$errorText = '';

		$pfile = fopen("includes/userpwd.txt","r");

		rewind($pfile);

		while (!feof($pfile)) {

			while ($line = fgets($pfile)){

			$tmp = explode('\n', $line);

			$tmp2 = explode(':', $tmp[0]);

	        echo trim($username) . " " . trim($tmp2[0]) . "<br>";

				if (trim($tmp2[0]) == trim($user)) {

					$errorText = $username . " SI ";

				} else {

					$errorText = $username . " NO ";

				}

				break;

			}

		}

		fclose($pfile);

		return $errorText;

	}