function aff()
{
var h="";
var w="";
if (document.all)
{
h=document.body.clientHeight;
w=document.body.clientWidth;

}
else
{
w=window.innerWidth;
h=window.innerHeight;
}

if(h<723)
{


}
else
{
var caltaille = h-724;
document.getElementById('vide').style.height= caltaille;


}
}