multi combobox related each other, how?

Question

Hello code gurus!

Briefly, I want to make four comboboxes,related each other.

For example, I will download a laptop vga driver. On the download driver section of my site, there is a combobox asking me to select the proper type of computer type like desktop pc, notebook, tablet. When I select notebook, second combo tuns active, it asks me to choose the proper driver for laptop like, sound, lan, vga. Finaly, after I select vga, the last combobox turns active and asks me to select the proper vendor for vga such as nvidia or ati. example is http://downloadcenter.intel.com/ , find by category section.

Any example, idea will be so helpful. I am waiting. Thanks already.