Php – The second argument to copy() function cannot be a directory

Anyone know why this:

<?PHP
$title = trim($_POST['title']);
$description = trim($_POST['description']);

// Array of allowed image file formats 
$allowedExtensions = array('jpeg', 'jpg', 'jfif', 'png', 'gif', 'bmp');

foreach ($_FILES as $file) {
  if ($file['tmp_name'] > '') {
    if (!in_array(end(explode(".",
            strtolower($file['name']))),
            $allowedExtensions)) {
      echo '<div class="error">Invalid file type.</div>';
    }
  }
}

if (strlen($title) < 3)
  echo '<div class="error">Too short title</div>';
else if (strlen($description) > 70)
  echo '<div class="error">Too long desccription.</div>';

else {
  move_uploaded_file($_FILES['userfile']['tmp_name'], 'c:\wamp\www\uploads\images/');
}

Gives:

Warning: move_uploaded_file() [function.move-uploaded-file]: The second argument to copy() function cannot be a directory in C:\wamp\www\upload.php on line 41

Warning: move_uploaded_file() [function.move-uploaded-file]: Unable to move 'C:\wamp\tmp\php1AB.tmp' to 'c:\wamp\www\uploads\images/' in C:\wamp\www\upload.php on line 41