passing data from js to controller

[eluser]Giorgio Nordo[/eluser]
I need to pass a data (just a numeric value) from a javascript function contained in a view to a controller.
I tryed to generate a cookie inside the javascript and to restore it inside the constructor of my controller by means of $this->input->cookie.
It seems that the value is not immediately available to the above CI method and in order to obtain the desired effect I have to manually refresh the page.
Obviously this is bad :-(

Some idea?