Need safety lock for front load washer, where to find one?

I'm searching for a safety lock for a front load washer/dryer. After hearing the news that a 4 yr old girl was accidently killed after climbing in a washer (her 15 mo old brother somehow turned it in) I am terrified this could happen and need a safety lock. I've never seen one in stores but did catch one on the nbc4 news during the story about the death today. I didn't catch the info on where to buy it though. Any thoughts?

I am sure you've got a bunch of responses so far but I thought I'd add mine just in case. It's only 16 bucks plus shipping and way worth it.

http://www.onestepahead.com/catalog/product.jsp?productId=535455&cm_ven=Froogle&cm_cat=NA&cm_pla=NA&cm_ite=14862

THANK YOU! My kids have crawled inside and I have been terrified of it for months!!!! I just ordered a lock for the washer and dryer! Thank you so much!!!!

I just saw one at Target yesterday. Here is the link:

http://www.target.com/Prograde-Front-Loader-Washer-Dryer/dp/B001FD3756/qid=1233773486/ref=br_1_2/187-9995287-4098948?ie=UTF8&node=13020251&frombrowse=1&pricerange=&index=tgt-mf-mv&field-browse=13020251&rank=pmrank&rh=&page=2