Bicycle Tutor

I just bought a used 20 inch bmx type bike for my son, nice bike but both brake levers are super loose and have a lot of wiggle room and give to them. The front brake will function when squeezed, but since the lever wiggles so much it doesn't seem very safe. I don't have much experience with fixing bikes, just wondering if anyone knows a simple fix.
Thanks a lot!!

Did you already try to tighten the levers up with the correct size Allen wrench ? Also Post a picture.

When you say "wiggle room" do you mean that you have to pull the lever a long way befor the brake blocks touch the wheel rims, or that the lever is lose in the pivot, or perhaps both?

There should be adjuster barrels on the levers that allow you to adjust the brakes so that the blocks are closer to the rims.

http://www.jimlangley.net/wrench/brake2.htm

If the pivot is lose/floppy then other than replace the levers with better, tighter ones, there's probably not much you can do.