How to teach "time out" when i want the playing to stop

Hi everyone

Whats the best way to teach "time out" when i want my 3 dogs to stop their games with each other and take a break?

Should i just call them to me or do as i'm doing at the moment (not very successfully) and use one command. I use "time out" ?

Thanks everyone

I dont know I call my girls and say "enough now" and they seem to respond, so I call first to get their attention and then tell them enough.. persitance is probably the key, hope someone with more info comes along soon
Rachel

Thanks Rachel, mine seem to stop for a mo and then start again. Mind you one is just 9 weeks old It's more for her that i want them to stop as they are so much bigger than her, they make her look so delicate.

Yeah we used the phrase time out, if they tried to dive back in, make the ach sound and then told them to lie down, when Rio was that young I used to crate her periodically after saying time out so she could sleep, and he could have some peace.

Same as above if the youngest doesnt listen you need to install a time out.

Thanks everyone you've convinced me now about the crate.
Hubby was against the idea of using it indoors as the elder 2 only go in their crates for car journeys. We have a dog room that they all sleep in at night. I wanted to use the crate so now it's coming out and going up so she can be crate trained early and also for a little den for her while she's growing.
She does have a den but it's a big box with a bed in