How to valid phone by Knockout Validation plugin ?

Add Knockout Validation reference into project from
https://github.com/ericmbarnard/Knockout-Validation

    self.Telephone = ko.observable("").extend({
        required: true,
        pattern: {
            message: '*Invalid Phone Number. (Format: 999-999-9999)',
            params: /\d{3}-\d{3}-\d{4}/
        }
    });

How many data binding context variables in Knockout?

http://knockoutjs.com/documentation/binding-context.html
$parent
$parents
$root
$data
$index (only available within foreach bindings)
$parentContext
$context
$element

How to bind array of string in Knockout?

$data
Example

How to avoid html tags flashing with Knockout data binding in the beginning?

Make a div to wrap up all of KO data binding elements, and make it invisible and only turn visible after KO data binding.

KO data binding tags in here ..

How to add prefix string in Knockout data binding?

ID is a observable
<h2 data-bind="text:'Transaction ID:'+ID()"></h2>

How to get index for foreach binding in Knockout?

The Syntax for get parent data index is:
$parentContext.$index