php session problem in IE 6.0

[chhangru@gmail.com]

i have this log in script from a book that uses session variable to
track the user.. everything works fine in firefox but in IE 6.0 the
page only refreshes and the user can be authenticated.. . i have tried
most of the solutions posted on the web.. but to no avail.. if anyone
can look at the code.. and help me..

thanks.. kelli

here are the scripts..
// stories.php
<?php
// Listing 26.5
// stories.php Is the Interface for Writers to Manage Their Stories

include('includ e_fns.php');
session_start() ;

if (!check_auth_us er()) {
?>
<form action="login.p hp" method="post">
<table border="0">
<tr>
<td>Username</td>
<td><input size="16" name="username" ></td>
</tr>
<tr>
<td>Password</td>
<td><input size="16" type="password" name="password" ></td>
</tr>
</table>
<input type="submit" value="Log in">
</form>
<?php
}
else {
$conn = db_connect();

$w = get_writer_reco rd($HTTP_SESSIO N_VARS['auth_user']);

print 'Welcome, '.$w['full_name'];
print ' (<a href="logout.ph p">Logout</a>)';
print '<p>';

$sql = 'select * from stories where writer = \''.
$HTTP_SESSION_V ARS['auth_user'].'\' order by created desc';
$result = mysql_query($sq l, $conn);

print 'Your stories: ';
print mysql_num_rows( $result);
print ' (<a href="story.php ">Add new</a>)';
print '</p><br /><br />';

if (mysql_num_rows ($result)) {
print '<table>';
print '<tr><th>Headli ne</th><th>Page</th>';
print '<th>Created</th><th>Last modified</th></tr>';
while ($qry = mysql_fetch_arr ay($result)) {
print '<tr>';
print '<td>';
print $qry['headline'];
print '</td>';
print '<td>';
print $qry['page'];
print '</td>';
print '<td>';
print date('M d, H:i', $qry['created']);
print '</td>';
print '<td>';
print date('M d, H:i', $qry['modified']);
print '</td>';
print '<td>';
if ($qry['published'])
print '[Published '.date('M d, H:i', $qry['published']).']';
else {
print '[<a href="story.php ?story='.$qry['id'].'">edit</a>] ';
print '[<a
href="delete_st ory.php?story=' .$qry['id'].'">delete</a>] ';
print '[<a
href="keywords. php?story='.$qr y['id'].'">keywords</a>]';
}
print '</td>';
print '</tr>';
}
print '</table>';
}

}
?>


///////login.php
<?php
session_start() ;

include('includ e_fns.php');
session_registe r("auth_user" );

if ( (!isset($HTTP_P OST_VARS['username'])) ||
(!isset($HTTP_P OST_VARS['password'])) ) {
print 'You must enter your username and password to proceed';
exit;
}

$username = $HTTP_POST_VARS['username'];
$password = $HTTP_POST_VARS['password'];

if (login($usernam e, $password)) {
$HTTP_SESSION_V ARS['auth_user'] = $username;

header('Locatio n: '.$HTTP_SERVER_ VARS['HTTP_REFERER']);
}
else {
print 'The password you entered is incorrect';
exit;
}


?>

// user_auther_fns .php
<?php
session_start() ;
function login($username , $password)
// check username and password with db
// if yes, return true
// else return false
{
// connect to db
$conn = db_connect();
if (!$conn)
return 0;

$result = mysql_query("se lect * from writers
where username='$user name'
and password ='$password'");
if (!$result)
return 0;

if (mysql_num_rows ($result)>0)
return 1;
else
return 0;
}

function check_auth_user ($auth_user)
// see if somebody is logged in and notify them if not
{
global $HTTP_SESSION_V ARS;
if (isset($HTTP_SE SSION_VARS['auth_user']))
return true;
else
return false;
}

?>