login validation

[corruption]

I think it is clear what i want this script to do. So it doesn't work. Any ideas?

<?php 
//connect to the databse
include 'db.php';
$username = $_POST['username'];
$password = $_POST['password'];
//run query to match the user attempting to login with one from the database
$sql = mysql_query("SELECT * FROM users WHERE username='$username' AND password='$password'");
$login_check = mysql_num_rows($sql);
// check if the user info validates the db

if($login_check > 0){
	while($row = mysql_fetch_array($sql)){
	foreach( $row AS $key => $val ){
		$$key = stripslashes( $val );
	}
		// Register some session variables!
		session_register('username');
		$_SESSION['username'] = $username;
		Header("Location: brothers.php");
	}
} else {
	echo "You could not be logged in! Either the username and password do not match or you have not validated your membership!<br />
	Please try again!<br />";
	include 'login.php';
?>

[planetsim]

Whats the problem can you specify what is happening?

You should also encrypt Passwords, i wouldnt want someone knowing my password.

[corruption]

the problem is that its not loggin in...it doesn't send it to the next page therefore i assume its not loggin in at least. Also i am going to encrypt the passwords once i allow them to create them. I'll use md5 encryption.