Auto Postback in Ruby On Rails

in some other language have a concept e.i "auto postback"

So, in Ruby on rails is there any such option e.i "auto postback"
or same as "auto postback"

basically what i want ot do is that i have 2 select box
One for "Industry" and other for "Chemical"

1st we show all the industry in "Industry" select box.
if we select any 1 industry from there, then the corrosponding
chemicals will b shown in the "chemical" select box...

please help me any one....

THankx

same as any other language: give the select box an onchange (or use observe_field/observe_form)

Fred

Thankx a lots....

will u please send me the proper syntax (if possiable 1 example) of
observe_field and observe_form

thanking You

Thankx a lots....

will u please send me the proper syntax (if possiable 1 example) of
observe_field and observe_form

Check out the api docs for them (api.rubyonrails.org)

Fred

thankx .... thankx a lots....