Port won't build because of installed conflict

[Ian FREISLICH]

Hi

[mini] /usr/ports/www/firefox # make

===>  firefox-3.6.10,1 conflicts with installed package(s): 
      firefox-3.5.13,1

      They install files into the same place.
      Please remove them first with pkg_delete(1).
*** Error code 1

Stop in /usr/ports/www/firefox.
*** Error code 1

But I don't want to be without the browser while I'm building the
new one.  Is there a reason why this conflict isn't checked at
install time rather than build time?

Ian

-- 
Ian Freislich