To sleep or not to sleep...in your bed!

How do you get your kids to stay in their beds at night? I don't mind having a kid sleep with us every once in awhile, but my daughter is in there every night. For the past few months she has not stayed in her bed the entire night. She goes to sleep fine and then around 12:30-1 she shows up. So any suggestions on how to keep kids in their own beds?? I think this is an issue we all deal with!