Welcome user_identity problem

I would like to place a message in the header so that when the user is logged in the message says Welcome: and their user name.

I am using the following code:

<div id=”mylogin”>

• <?php { if ( ! is_user_logged_in() ) echo (”); else
  echo (‘Welcome: ‘ .$user_identity) ;} ?>
  <?php {if ( ! is_user_logged_in() )
  include (TEMPLATEPATH . ‘/loginform.php’); else
  $link = ‘| ‘ . __(‘Logout’) . ‘‘;
  echo apply_filters(‘loginout’, $link);}?>

</div>

Orginally this code was placed embeded on the same page as the post. It worked fine. But then when I seprated the header as different file and then used the
<?php get_header(); ?> function to pull it in, it doesn’t work.

Please let me know why.

Thank you,
–Akram Taghavi-Burris