If you were using Internet Explorer 6 or 7 on a Windows machine or Opera 9, this demo would actually work!
Intro
Validation
Date and time types
Range control
Repetition
Calculated fields
Datalist
Autofocus
Prefilling forms
Roundtripping data
Input mode

Data roundtrip

Traditionally submitting a form has the effect that a new document is returned and replaces the current page in the browser window.

In WF2 it is possible to submit the data form the form, and have the server return data that replaces the values in the form field without the whole page beeing replaced.

This form is hooked up to a service which reverses the content of text fields.

Your name:

The HTML look like this:

<form action="reverse.asp" replace=values>
Your name: <input name=txt1 value="Simsalabim!" type="text">
<button type=submit>Reverse!</button>
</form>

It is the attribute replace=values which declares that formdata should be extracted from the returned document. The default corresponds to replace=document, which means that the returned document replaces the current page.

When using replace=values, the server must return the data in a specific XML-format, which looks like this:

<?xml version="1.0"?>
<formdata xmlns="uuid:d10e4fd6-2c01-49e8-8f9d-0ab964387e32">
<field name="txt1">!mibalasmiS</field>
</formdata>

The format is called XML-formdata, and may also be used for prefilling forms with data from an external source.