Adding dependent field values

Adding dependent field values

Hi,

I'm at the very early stages of setting up Zoho Desk but can't find how to enter ticket category values such that sub-categories displayed are dependent upon the selected category.

I have both category and sub-category fields on my ticket layout and can add values to each but on entering a ticket all sub-category values are displayed regardless of the selected category.

I've tried various searches on the KB/Community without success.  I'm sure the answer is there somewhere and is very simply I'm just not seeing it.

Thanks.