OS X GNU Screen Proper Bash Prompt

How to get GNU Screen working properly in Mac OS X.

~/.bashrc

alias screen='export SCREENPWD=$(pwd); /usr/bin/screen'
export SHELL='/bin/bash -rcfile ~/.bash_profile';

case "$TERM" in
    'screen')
         cd $SCREENPWD
         ;;
esac

~/.screenrc

startup_message off
shell -$SHELL