Cross Price Elasticity

Dear all,

I'm trying to estimate cross price elasticities of a non linear logtransformed model. Do any of you know how to estimate the cross price elasiticy in stata? In addition to the prices and number of quantity sold, I have six different dependent variables. The dataset includes 500 drugs divided into generic og original. I want to estimate the cross price for generic and original drugs in each of the 500 drugs types.

I'm forever grateful,

Kathrine