what's happened with this javaScript code
 

Hi,
I just downloaded 2 Mootools.js files. both of them are version 1.1 and they do the same. but I wonder why first one is 72 KB and second one is 34 KB.

I want to know what's happen with the second file with less size, Is is compressed, Gziped, encrypted or something else and how can i do the reverse. I mean how can i convert a code like the one with 34 KB to the source file.

I attached both files and I really appreciate if some one can help me.

They're both compressed to some degree although the second one has been both fully compressed and obfuscated while the first one seems to be extra-space and randomly new-line compressed.

This site here is a favorite of mine and does a good job on your first js file: http://elfz.laacz.lv/beautify/

However, once a script file is obfuscated (variable and object names reduced), it's near-impossible to make sense of it unless you know specifically what's going on (or you have hours of spare time) and so your second JS file is a bit more difficult to decipher.