function showHideSousNav(id)
{
 if ( id == "descr" )
 {
  //document.getElementById("descriptif").style.display="block";
  //document.getElementById("plus").style.display="none";
  document.getElementById("odescr").className = "actif";
  document.getElementById("oplus").className = "";
  document.getElementById("oloc").className = "";
  document.getElementById("ocoords").className = "";
 }
 else if ( id == "plus" )
 {
  document.getElementById("odescr").className = "";
  document.getElementById("oplus").className = "actif";
  document.getElementById("oloc").className = "";
  document.getElementById("ocoords").className = "";
 }
 else if ( id == "loc" )
 {
  document.getElementById("odescr").className = "";
  document.getElementById("oplus").className = "";
  document.getElementById("oloc").className = "actif";
  document.getElementById("ocoords").className = "";
 }
 else if ( id == "coords" )
 {
  document.getElementById("odescr").className = "";
  document.getElementById("oplus").className = "";
  document.getElementById("oloc").className = "";
  document.getElementById("ocoords").className = "actif";
 } 
 ancre(id);
}