overnight upgrade interrupted by questions

[Pollywog]

I did 'portupgrade -aP' last night but this morning I found that one package 
had some questions for me about how I want to compile the package (wants to 
know which options I want).  This meant that no packages were compiled since 
the cups package asked questions.

Is there a way to circumvent this problem when upgrading with portupgrade?
I know how to avoid this when installing a single port but not how to avoid it 
when upgrading all available packages.


thanks