How can I post data (form) to html page and hijacking the data in the middle?

Question

the site addres: http://www.ynet.co.il/YediothPortal/Ext/TalkBack/CdaTalkBack/1,2497,L-3650194-0-68-544-0--,00.html

1. fill the form with rubbish.
2. Hit 'Send'
3. the form post the data to another HTML without any parsing of the data i've just added

How do they do it?

Answer 1

Edit based on clarified question:

Numerous frameworks can be configured to intercept an html request - for instance asp.net can be set to handle any given extension and an HTTPModule could do anything with that. It's really up to web server configuration what it decides to do with any request.

also: you don't really want to be saying "hijack"

Answer 2

A likely option is that they are using a content management system where "html" on the URL doesn't actually mean it's a static html file.

Answer 3

This may be out of left field, but I've certainly used the occasional JS function to grab everything in the header and either parse it or pass it to another script using AJAX.

I'll sometimes use this method in a 404.html page to grab the headers of the previous page, parse them out to see where someone was trying to go and redirect them.

That is, as annakata said, one of the numerous options available.