Size manager

[justoneweek]

Hi,

I'm making a site with the version 1.4.8.3: http://www.numero00.com/

How can I manage differnt size?

 

For example: if I have a t-shirt of different size (XS - S - M - L - XL) and I create one product, when I finish M and L how I do? The product will be already available?

 

Hope I explaing good :/

 

Many thanks!