Just say no to lame encryption! While useful as a learning exercise, posting weak encryption code in a public forum like this just invites some poor newbie to come along and use it. Yes, even though you tell us it's lame I bet someday someone will come and cut and paste your code. I have seen a seemingly competent programmer do that with an XOR snippet he found to send "encrypted" credit card data over email. If you don't really understand encryption and aren't using a well validated library, then you shouldn't be using encryption at all.
Practice writing this stuff at home but please don't share with everyone.