Basic elisp question: bind key to function with arg

[Tory S. Anderson]

I have the following in my emacs init, and it works fine: 

    (global-set-key [C-up] 'enlarge-window)
    (global-set-key [C-down] (lambda () (interactive)
                               (enlarge-window -1)))

But it seems awkward to me that I need to add all the extra just to pass a -1 
arg to the function, so I'm suspecting there's a simpler way to write this. Any 
tips?