I don't get the JS error, I just don't see the images.
On the second line of your cos.js file there is this:
var accepted_domains=new Array("cos.purple-cow.org")("purple-cow.org/cos")
Looks a bit wrong to me. Change it to this and see if it helps:
var accepted_domains=new Array("cos.purple-cow.org", "purple-cow.org/cos");