Not sure I know what you mean by SKU?
What I'm trying to do is have a drop down list for each bag of food, with the three weights and prices. Each type of food has different prices for the different weights. The examples for ecart have not shown me how to do this however Jason from tech support was able to help get the drop down working correctly with me.
My big problem right now is that once I have all the drop downs and ATC buttons in places they are working correctly individually but like I stated, if you get one small bag of the large bite chicken and one small bag of the small bites chicken you only have one line stating say small bites chicken with a quantity of two. When it should be two lines in the cart with one line for a small bag of chicken lagre bites and one line for small bag chicken small bites. Even though these are the same price its two different items.