defun not working

[Baloff]

Hello
I have this in my ~/.emacs

(defun edo-vertical-to-horizontal ()
(interactive)
(let ((one-buf (window-buffer (selected-window))))
(other-window 1)
(delete-other-window)
(split-window-horizontally)
(switch-to-buffer one-buf))

upone M-x edo-vertical-to-horizontal
it actually do horizontal to vertical which is the opposite to what it 
is suppost to do. it was working good last time I used it which was a 
year or so ago, I since upgraded my debain.

not sure why it would do this.

thanks