Understaning Javascript prototype

http://stackoverflow.com/questions/8093057/javascript-inheritance-and-the-constructor-property/8096017#8096017

http://yehudakatz.com/2011/08/12/understanding-prototypes-in-javascript/

http://stackoverflow.com/questions/14545210/why-prototype-is-undefined

http://stackoverflow.com/questions/4841175/trying-to-understand-the-point-of-prototypes-in-javascript

http://stackoverflow.com/questions/572897/how-does-javascript-prototype-work