if (document.images) {            
img1on = new Image();img1on.src = "images/accueil_on.gif";img1off = new Image();img1off.src = "images/accueil_off.gif";
img2on = new Image();img2on.src = "images/nous_joindre_on.gif";img2off = new Image();img2off.src = "images/nous_joindre_off.gif";

}
function imgOn(imgName) { if (document.images) {document[imgName].src = eval(imgName + "on.src"); }}
function imgOff(imgName) { if (document.images) { document[imgName].src = eval(imgName + "off.src"); }}