it is possible to add condition for the quantity of product ?

[jemmeli]

hello everybody 

 

it's long long time to me really I miss this great forum, friends I have a question: 

 

it is possible for me to add condition for quantity product I want to buy them : I have certain products and I want to buy them   by two , four or six product.

 

if it is possible how can I do that ? and thank you a lot in advance