function visibilite(thingId)
{
var targetElement;
targetElement = document.getElementById(thingId) ;
if (targetElement.style.display == "none")
{
targetElement.style.display = "" ;
} else {
targetElement.style.display = "none" ;
}
}
 
var imageid;
 
function swapImage(imid) {
imageid = document.getElementById(imid) ;
 
if (imageid.src == "http://www.planet-opera.com/icones/plus.png")
                {
                imageid.src = "http://www.planet-opera.com/icones/moins.png";
                }
else if (imageid.src == "http://www.planet-opera.com/icones/moins.png")
                {
                imageid.src = "http://www.planet-opera.com/icones/plus.png";
                }
}