raising the font size in dialog boxes, howto?

[Peter Alcibiades]

How do you raise the size of the font in dialog boxes, answer and ask, on 
account of people not being able to see them very well?  You can do this 
somewhat by changing the size of the rev ui elements from the application 
browser, but its one at a time, so very laborious, and also you don't seem 
able to change the message font.  As in

answer "xxx" with "aa" or "bb"

You can change the font of aa or bb but apparently not of xxx.  Also the 
box into which the aa or bb goes does not seem to change quite correctly to 
accomodate the font.  And the old familiar problem of not all fonts on the 
system being available shows up here again.

Is there a global setting for this stuff someplace ?  Or does one have to 
simply write one's own dialogue boxes from scratch if he wants a different 
font size, and wants to change the xxx?

Peter