var nbreban = 2 ;
var nbrealea = Math.random() ;
var alea1 = Math.round( (nbreban-1) * nbrealea) + 1 ;
bannieres = new Array
bannieres[1] = "<a href=\"http://www.atbr.org\" alt=\"Le site de l'ATBR\"><img src=\"http://www.atbr.org/bannieres/atbrbanner.gif\" border=\"0\" width=\"468\" height=\"60\" title=\"Le site de l'ATBR\"></a>"
bannieres[2] = "<a href=\"http://www.atbr.org\" alt=\"Le site de l'ATBR\"><img src=\"http://www.atbr.org/bannieres/atbrbanner2.gif\" border=\"0\" width=\"468\" height=\"60\" title=\"Le site de l'ATBR\"></a>"
var banniere = bannieres[alea1]