store value temporarily in controller and retrieve that value on each time page refreshed

[eluser]jakelehner[/eluser]
You're storing the values in the user's session, but always pulling them from the POST data. When you refresh, you lose your post data.

Quick and dirty, use flash data instead of the session user data. At the top of the controller you can use an if statement to see if the POST data is populated. If so, take the values from there. If not, try and get it from the flash data. If that doesn't work, throw an error.

And, of course, you'll need to reset or persist the flash data every time since it's only available for one page load.