Bind the value of a function to a variable (was: window-height function lies!)

[Rodolfo Medina]

Nikolaj Schumacher <me@nschum.de> writes:

> You might want to use:
>
> (1+ (count-lines (window-start) (window-end)))



Thanks.
I want to try to bind this to a variable, but don't know the right syntax.  I
want to do something like:

(setq scroll-default-lines (1+ (count-lines (window-start) (window-end))))

, but get error.  How can I do that the right way?

Thanks
Rodolfo