interaction terms in conditional logit.

[Khalidjoya]

I am doing a research on the title of "Demand for Food Safety attributes for Vegetables" using a discrete choice experiment and conditional logit regression in SAS I want to know how I can use the interaction terms in conditional logit using SAS?

[Ksharp]

Just add interaction effect in MODEL ?

proc logistic;

strata ......

model y=x z x*z ;

OR

proc glimmix

model y=x z x*z;

random ......

[Khalidjoya]

I have tried this with Proc MDC but it didn't work and it needs class statement.