Thanks. I was able to get what I wanted by doing this:
predxn <- function(s,d) { coef(m3)[1] + coef(m3)[2]*s + coef(m3)[3]*s^2 + coef(m3)[4]*d + coef(m3)[5]*d^2 }
But it's not very elegant...
// joseph w. clark , phd candidate
\\ usc marshall school of business