Need LISP Help: popping up speedbar only under X

[Dan Anderson <dan@mathjunkies.com>]

If I evaluate:

(speedbar t)

The speedbar pops up.  But I want it only to pop up when I'm running it
in KDE, and thus under X.  So I tried:

(if (eq window-system "x")        ;; open the speedbar when emacs loads
    (speedbar t))                 ;; if we're under X

And it doesn't work.  According to M-x describe-variable:

A symbol naming the window-system under which Emacs is running
(such as `x'), or nil if emacs is running on an ordinary terminal.

What am i doing wrong?

Thanks in advance,

Dan