model{
for(i in 1:n){
  FEV[i] ~ dnorm(mu[i],tau)
  mu[i] <- beta[1] + beta[2]*Age[i] + beta[3]*Smoke[i]  + beta[4]*Age[i]*Smoke[i]
  CPOinv[i] <- sqrt(2*3.14159/tau)*exp(0.5*tau*pow(FEV[i]-mu[i],2))
  }
beta[1:r] ~ dmnorm(betastar[1:r],C0inv[1:r,1:r])   # BCJ prior
tau ~ dgamma(a,b)
}