RJS form field enable / disable etc

Hi All,

I guess I am looking for the preferred methodology for enabling /
disabling form elements. I should add that my enable / disables are not
simple in the sense that a drop down selection should cause various
other form elements to enable or disable in various combinations.

So my question is, what does the ROR person use to make this work? I
have seen the mention of RJS, but doesn’t that result in the AJAX with
the server? Just to enable / disable form elements? Seems odd.

Is straight javascript the way to go?

Any comments or suggestions are appreciated,
Rick