function cache_pub (pub_interstitiel){
var affichePub = document.getElementById(pub_interstitiel); 
affichePub.style.visibility = "hidden";
}

function interstitiel (pub_interstitiel){
var temps_milli_secondes = 9000;
var div = pub_interstitiel;
var affichePub = document.getElementById(div);
affichePub.style.visibility = "visible";
setTimeout ("cache_pub ('pub_filiere')", temps_milli_secondes); 
}