JavaScript Property vs Label?
===

If I write in Javascript : 

    var o= { aaa :s };

How does he know to distiguish between 

1) label named `aaa`  

![enter image description here][1]

2) property named `aaa` ( IMHO  , properties _can_ be used without `"`)


  [1]: http://i.stack.imgur.com/V2mkE.jpg

 