function manageVis(id){
  if(document.getElementById("div_"+id)){
    if(document.getElementById("div_"+id).style.visibility!="visible"){
      if(navigator.appName.substr(0,3)=='Mic')
        document.getElementById("div_"+id).style.display="inline";
      else
        document.getElementById("div_"+id).style.display="block";
      document.getElementById("div_"+id).style.visibility="visible";
      document.getElementById("img_"+id).src="IMG/moins.gif";
    }else{
      
      document.getElementById("div_"+id).style.display="none";
      document.getElementById("div_"+id).style.visibility="hidden";
      document.getElementById("img_"+id).src="IMG/plus.gif";
    }
  }
}