In order to install solaris package without having to answer all sorts of questions from the package manager, you need to create an answer file. For the screen package, I used the following data:
Package file: screen-4.0.2-sol8-sparc-local
Answer file: screen-4.0.2-sol8-sparc-local.answer
mail= instance=unique partial=nocheck runlevel=nocheck idepend=nocheck rdepend=nocheck space=nocheck setuid=nocheck conflict=nocheck action=nocheck basedir=default
And to install the application I used the following command:
pkgadd -n -a screen-4.0.2-sol8-sparc-local.answer -d ./screen-4.0.2-sol8-sparc-local SMCscreen