How do you stop shoe laces from slipping loose?

I am using the product called Knot Locker by Playantra, it is a small

shoelace accessory which fits to your existing shoelaces, no gluing or

tools required. It will secure your shoelace knot and it will not become

loose, check out their website, I am using Snap button version, it is a great

product,

http://www.playantra.com

Hope this helps...