function initialisation() {
var obj1=document.getElementById("lien1");
obj1.onmouseover=fond1;
obj1.onmouseout=fond2;
var obj2=document.getElementById("lien2");
obj2.onmouseover=fond1;
obj2.onmouseout=fond2;
var obj3=document.getElementById("lien3");
obj3.onmouseover=fond1;
obj3.onmouseout=fond2;
var obj4=document.getElementById("lien4");
obj4.onmouseover=fond1;
obj4.onmouseout=fond2;
var obj5=document.getElementById("lien5");
obj5.onmouseover=fond1;
obj5.onmouseout=fond2;}
function fond1() {this.className="on";}
function fond2() {this.className="out";}