Help with keybinding to delete between {}

[lampshade]

Hello,


I would really like a keybinding that would allow me to delete any
text between sexp's like {} (), etc no matter where I am between them
and whether or not that text has spaces.

For example
{asdfdsfa asdfasdf asd}
I would like to delete between leaving only the {} with my cursor
inside ready to type.  So far I've been trying
(defun delete_between ()
        (interactive)
        (backward-sexp)
        (kill-sexp))
(global-set-key [(control meta k)] 'delete_between)

but that doesn't quite work.  Anyone have any improvements or help
they could give me?

Thanks in advance,
lampshade