Drupal 6 - user picture imagecache

<?php
// imagecache preset for user picture
function assistng_user_picture($account, $size = 'user_picture') {
  if (
variable_get('user_pictures', 0)) {
   
// Display the user's photo if available
   
if ($account->picture && file_exists($account->picture)) {
     
$picture = theme('imagecache', $size, $account->picture);
    }
   
// Provide default image
   
else if (variable_get('user_picture_default', '')) {
     
$picture = theme('imagecache', $size, variable_get('user_picture_default', ''));
    }
    return
'<div class="picture">'.$picture.'</div>';
  }
}
?>