plot-function: How to change the font of the titles

Hello!
I want to create a plot with x- and y-labels writen in times or arial.
How can I change the font?

Well, is it `titles' (subject) or `x- and y-labels', and if the latter do 
you mean 'labels' (as in axis) or 'xlab' (as in title)?

Do you want some or all of the annotation in Times or Arial, or some in 
each.  (On devices which support Arial it is the default.)

And on which device and which version of R?

If this is on Windows, see the rw-FAQ and the help on Rdevga, and choose 
an appropriate value of the graphics par 'font' (normally 1 for Arial and 
6 for Times).  Otherwise, consider par(family).

[And please do read the posting guide and not send posts twice or more.]

Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595