HOW Make dependents combobox or dorpdownlist's

[julio-7-4-80]

Hello everybody, i need another help

i'm triyng to do the next in flex: using DropDownList or Combobox and Mysql DB, I
want select to a brand of a product, then a caracteristics and then a detail s of that brand ... and i want to make it using dependents combobox's or dorpdownlist's

I upload my project and i need help. is very important, please...

all that i want is made dependents combobox or dorpdownlist.
there are 2 links into megaupload:

Project : http://www.megaupload.com/?d=X6V25N8O
DataBase : http://www.megaupload.com/?d=T6TLI3OL

Please i need help this i have to finish this point to start with
another point.