Personal loan: How do I make sure to get paid ?

[Andy H.]

I saw someone on Craiglist posting he need emergency money. Willing to pay interest on loan, need money for 45 days. Since the amount is relatively small, I want to help him. How do I make sure I get paid ? Do I use a promissory note ? What is the best way to protect myself or is this a scam and I should just ignore it ? Any help is greatly appreciated. Thanks.