For Homework Tonight

How in the world do you get kids to complete homework? My current system is to check their homework for completion on a random basis and award them points if they have completed it and no points if they haven't. Note this is just for doing it not necessarily doing it correctly. This system makes my life easier because I don't have to grade individual problems all the time nor waste class time checking it everyday, but hopefully the thought of it being checked is enough to make the students do it every night. Instead it has become a game of I'll try and guess when he is going to check the homework and only do it then, or even I'm just not going to do it at all. I even started giving homework quizzes in my one class when less than half the students did their homework and it did nothing but punish the kids who actually did the work because they have trouble understanding it but worked hard anyway. How can I make them see that homework is useful and is helping them learn the material and that it is worth doing well and not just scribbling something down for credit?