Starting screen from logon script

Hi

I have an embedded device that I want to start screen during an ssh logon.

I have the following script.

#!/bin/sh

SCREENRUNNING=`pgrep SCREEN`

if [ -z "$SCREENRUNNING" ]; then

    echo "Screen not running so let's start the Master session
    sleep 2
    screen -dmS Master
    sleep 2
    screen -x root/Master


else

    echo "Screen is already running let's connect to existing session"

    sleep 2
    screen -x root/Master

fi

This starts screen correctly without problems and gets called from
/etc/config/profile when you do a ssh logon.

However this script stays active until screen is fully shut down, this
is a problem as when you detach from the session and then logoff the
device you end up leaving orphaned scripts each time you log back on.

Is there a way to start the screen -x root/Master session and still
allow this calling script to finish?

Thanks