Namespaced screen with separate bash history

myscreen.sh

set -e

NAMESPACE=${N:-${NAMESPACE:-default}}

echo "************************************************************************************************************"
echo "This screen session is for namespace \"${NAMESPACE}\" "
echo "If you are not the owner of this namespace please exit now (Ctrl-C) , thanks :)"
echo "If you want to use your own screen namespace, use: NAMESPACE=yourname $0 or N=yourname $0" 
echo "Press ENTER to continue or Ctrl-C to exit"
echo "************************************************************************************************************"
read

export HISTFILE=$HOME/.bash_history_${NAMESPACE}
touch ${HISTFILE}
screen -dr ${NAMESPACE} || screen -S ${NAMESPACE}