[PHP] Dependent selections

[Raúl Castro Marín]

Hello, I'm trying to find the best way to implement Dependent selections -for 
instance, like countries and states tables-. I found this nice example 
http://www.ashleyit.com/rs/jsrs/select/php/select.php. But this method require 
to go to other page to refresh vars php. I would like have a method (I think 
with Javascript) that don't need to go to other page as possible. 
I hope you help me,  regards!