cascading drop down box implementation without ajax in ruby on rails

Question

I am newbie in RoR and creating my first project. I have two models category and article.category has many article and article belongs to one category.I want to create cascading drop down boxes to display article.In first drop down box I want to select category which update second drop down box with articles which belong to the category.As no of articles and categories are less so I don't have to use ajax.Please guide me how to implement the functionality without ajax.Should I create a function in application controller and then call the function on onChnage event on drop down boxes and if this is correct the how to implement this??