How can I get my two daughters to sleep in the same room together.?

I have two daughters, one is 6 yrs old and the other is 2.5. My wife and I try to have them in bed every night by 7:30. Our bed time routine is as follows: first the girls get into their pajamas, then they brush their teeth, then my wife or I sing bedtime songs, then it is bed time. We don't have any trouble with the girls leaving the room, but they will get out of bed and have a huge party in the floor. We have to go in over and over again to put them back in bed and tell them to be quiet. We have tried taking away toys,TV,sweets; still no results. Any suggestions would be greatly appreciated.