jQuery().ready(function(){

var bann = new Array ();
bann[0]="https://img11.hostingpics.net/pics/1749961370623799cosmo3.png";
bann[1]="https://img11.hostingpics.net/pics/7293651370718191cosmop2.png";

var i = Math.floor(2*Math.random());

document.getElementById("bann").innerHTML = "<a href=\"lien_du_forum\"><img src=\""+bann[i]+"\" alt=\"mon forum\" border=\"0\"></a>";
});