JavaScript Getters and Setters

IE 9: Object literal syntax & Ojbect.defineProperty (any object)
Object.getOwnPropertyDescriptor() method to query getter and setter methods

IE 8: Object.defineProperty (DOM objects only)
Object.getOwnPropertyDescriptor() method to query getter and setter methods

IE 7: closure

Other New: Object literal syntax & Ojbect.defineProperty (any object)
In WebKit Object.defineProperty does not work with DOM objects.

Other Old: Object literal syntax & __defineGetter__() & __defineSetter__() & closure
__lookupGetter__() & __lookupSetter__()