How to add new fields in cart of VirtueMart (Joomla!)

I am working o开发者_JS百科n joomla and using joomla VirtueMart component.I created new fields in product detail page like color and size (drop down), Now I want to add that POST value (ex. $_POST["cmbColor"]) in shopping cart process and finally to be saved in database of VirtueMart.Please help me how to add these fields in cart.

Did you use the attribute system to add the optional color and size? Using either child products or attributes will get the options to show in the cart and saved on a sale. The VM documentation is pretty good on this topic, you can find how to use attributes here -

http://virtuemart.net/documentation/User_Manual/Product_Attributes.html