The with binding
    

With bidning with alternative synatx

Wife's first name: .
Wife's last name: .

        Computed observables
    

The first name:
The last name:

what if we want to work with the full name of a person as a single entity?
The computed observables would help us.
Computed observables are special calculated properties. They depend on one or more
other observables, and will automatically update after any dependencies change.
    

The full name: (coming from a copmupted view model prop)

    Writeable Computed Property

The full name: (coming from a Writeable Computed Property view model prop)

    http://knockoutjs.com/documentation/computed-reference.html    
    http://knockoutjs.com/documentation/computedObservables.html    

Some cool ko stuff

    observable array - The one important thing is that an observable array tracks the
    objects in the array, not the state of those objects. So, if you create an observable array
    from objects, it doesn't mean that these objects will also be observables.

Adding to an observable array

New Child: Add

Person's children: - YOU CAN SELECT MULTIPLE (OR ONE) and Remove them from the observable array of children

Remove

alert number of currently selected in the above select tag

    http://jsfiddle.net/rniemeyer/nX4xj/
    And
    http://jsfiddle.net/AZ9Cn/ - Better exmaple 
    And
    http://www.tutorialspoint.com/knockoutjs/options-binding.htm