After exiting custom startup shell script, exit into default startup shell?

You have to excuse me if I use the wrong language here of if I'm asking an obvious but that is, after all, why I'm here.

I'm just getting to grips with shell scripting and have written a small script that is "Run as a custom command instead of my shell" to make things a little easier for the things I might want to do. Here's what I've got.

#
# Custom console startup script.
#

path_to_scripts=~/Scripts

echo "Hello $USERNAME, what would you like to do?"
echo "Options:"
echo "-l        Continue in local machine"
echo "-s        Connect to server"

read response

case $response in
    "l")    echo "Contunie within local machine.";;
    "s")    $path_to_scripts/connect_to_server;;
    *)      echo "Invalid command. Exiting.";;
esac

So my terminal starts up with this script and if I select 's' it runs the 'connect_to_server' script fine and connects then I'm in!

However when I enter an invalid command, or key in 'l' to exit and continue as normal the console says 'The child process exited normally with status 0.'

I know that it has just quit and the script has exited but what I want to do is just run the default shell so that I am then in my local ma开发者_如何转开发chine at ~, as if id just started up console with default settings. What do I need to run in order to do this?

Run exec "$SHELL" to replace the current process with your normal shell.