a problem of the jinsaw game write by the html

Tweet

I found a jinsaw game which write by html on the internet There's a problem of it I want to know what's the function of the code from "pos[1]=7" to "pos[15]=15" Because the code can't be pasted,if put it in my blog "bobsheep.blogbus.com" The log's name is start by "HTML" you can find it easy ps.My English is poor.If there's some mistakes,tell me ,I'll change it.THX