Thread: sub custom fields

sub custom fields

Hi all.
My english is not perfect but i will try my best to explain what i need!

I made a custom field "model" in category name "cars for sale" so members can choose the model of the car they want to sell!
But i would like to give them more option coz in "model" field they can choose like ( Audi, MB, Suzuki... ) but they cant choose what kind of Audi or what kind of MB or Suzuki they want to sell!

So i would like to have it like this : when i member choose for exemple "Audi" from "model" field a new field will show up under that wich shows different type of "Audi"
and if the choose "Suzuki" in first field the new field show only different type of "Suzuki"

Thanks alot.