Tag + Cat system like newegg

[Mgccl]

www.newegg.com
I say Newegg.com's system, and I thought about it and think it is a Catgory system and Tag system work together...
where Item linked to tags and tags linked to catgorys
so under one catagory there can be many more catagory that countain the tags happen to be on one of the idea in the 1st catagory....
SO... I want to make somethign like that and here is my proposal

first there are a database called cat

id|cat

and tag

id|tag

and item

id|item

and tag cat link

cat_id|tag_id

and a tag to item link

iteam_id|tag_id

and here I got a problem... How to get each cat and make each cat work with each tag. and also contains more cat inside it which have tags tagged a item on the other cat.....
if I explained poorly... here is a easy way out....
HOW TO MAKE THE newegg.com like catagory + tag system
I know how to make the backend and database structure...
BUT I can't think of a way to make the front end!

[bogu]

What do u understand by tag?

I see there menu like: categories that have subcategories and items in the subcategories ...

If u want to have a menu with categories and subcategories, u should have a table like:

table categories:

| ID | categ_id | name |

ID is a PK (primary key, autoincrement)

categ_id is an integer, wich is 0 if the category is a main category or not 0 if is a subcategory and will have the value of the category ID that contains it ...

name a varchar (the name of the category)

table items:

| ID | categ_id| name | ....

ID is a PK (primary key, autoincrement)

categ_id will be the category ID in witch the items will be (this is how the tables categories and items will link)

name a varchar (the name of the item)

.... <- the rest of the item properties ...