Well, you haven't said what isn't working or what you're trying to do (that's why you should have comments in your script!), but I'm guessing it doesn't run the "backup" or the "restore" scripts, which are ones that are in your /home/ubuntu directory?
You probably need to have the full path, so rather than using "cd", just run "/home/ubuntu/backup" and "/home/ubuntu/restore"
Also, why do you have a "read" after? Don't you just want to exit after they've chosen a valid option?