cant retrieve session vars

#!/usr/bin/perl -w

use strict;
use includes::User;
use DBI;
use CGI;
use CGI::Session;
use HTML::Template;

my $cgi = new CGI;
my $session = new CGI::Session(undef, undef, {Directory => 'sessions'} );
my $sid = $session->id();
my $username='whatever';
$session->param(username, $username);
my $cookie = $cgi->cookie(CGISESSID => $sid);
print $cgi->header( -cookie=>$cookie);


######################################
# FILE 2
######################################

#!/usr/bin/perl -w

use strict;
use includes::User;
use DBI;
use CGI;
use CGI::Session;
use HTML::Template;

my $cgi = new CGI;
print $cgi->header;
my $sid = $cgi->cookie("CGISESSID");
print "sid is $sid<br>";
my $session = new CGI::Session(undef, $sid, {Directory => '/tmp'} );
my $username = $session->param("username") || die('No Username');

# $username just doesn't exist :/