When the user presses Back button in browser, the viewmodel breaks

[tomasherceg]

1. The user fills some form controls (e.g. textbox).
2. The user navigates to another page.
3. The user presses Back button in the browser.
4. The browser fills the form controls with the values automatically but in the viewmodel there is null on each property.

It happens in Google Chrome and maybe in other browsers.

[tomasherceg]

The viewmodel should be saved into a hidden field in the page when the user is leaving the page to be restored when the user clicks the Back button in the browser.