cleaned up your code and malformed syntaxes in the HTTP requests, it works now.

Code:
Alias Update {
  if ($sock(update)) sockclose update
  sockopen update www.takkra.nl 80
}

on *:sockopen:update:{
  sockwrite -n update GET /cb/test.txt HTTP/1.1
  sockwrite -n update Host: www.takkra.nl
  sockwrite -n update $crlf
}

on *:sockread:update:{
  var %r
  while (reading) {
    sockread -f %r
    if ($sockerr) {
      echo -a Socket error $sockerr
      break
    }
    echo -a Data: %r
    if (!$sockbr) break 
  }
}