creating variable.....?

Hi RoR developers,

I have selection which is not in form object. do you have any idea how to assign the value of selection to variable. I want to write something var select= document.selectionid.value;

is it possible to write ?

and I have another question which is about params[:id] too.

is it possible call the params[:id] of selection which is not in form object, from controller, can we assign it to variable? like

@name=params[:id]

thanks for any commends