model {

for(i in 1:N){

mu_M[i] <- alpha*x[i]
M[i] ~ dnorm(mu_M[i],prec1)

mu_y[i] <-c*x[i]+beta*M[i]
y[i] ~ dnorm(mu_y[i],prec2)
}

alpha ~ dnorm(0.0,0.000001)
beta ~ dnorm(0.0,0.000001)  
IE<-alpha*beta
c ~ dnorm(0.0,0.000001) 
DE<-c
var1 ~ dgamma(1,0.1)
var2 ~ dgamma(1,0.1)
prec1 <-1/var1
prec2 <-1/var2
}