My Son Deletes All The Missions I Accomplished

As i've been playing both Grand Theft Auto Vice City and Liberty City Stories these past few weeks, i've accomplished quite a fair number of missions. After completing these missions, i saved the game.

My son went to delete all these game stages which i had saved.

Crap. Now i have to replay all these stages from the beginning again.

He and his itchy hands.

I need to get another memory stick to store all these game stages to prevent him from deleting them again.

Would probably get another 4GB stick, as 8GB is terribly expenisve at $100+.

With a separate memory stick, i can bar him from playing the GTA games, since they are not meant to be played by a 5-year-old anyway.