function makeArray(n) {
this.length = n;
for (var i=1; i<=n; i++) {
this[i] = ""; 
}
return this;
}
var i;
function imagealeatoire() {
i = Math.floor(4 * Math.random() + 1);
return image[i];
}
image = new makeArray(4);
image[1]="images/midinor.jpg";
image[2]="images/tirlest.jpg";
image[3]="images/tol_div.jpg";
image[4]="images/out_eqip.gif";