var imagenumber = 11 ;
var randomnumber = Math.random() ;
var rand1 = Math.round( (imagenumber-1) * randomnumber) + 1 ;
images = new Array
images[1] = "1s.jpg"
images[2] = "2s.jpg"
images[3] = "3s.jpg"
images[4] = "4s.jpg"
images[5] = "5s.jpg"
images[6] = "6s.jpg"
images[7] = "7s.jpg"
images[8] = "8s.jpg"
images[9] = "9s.jpg"
images[10] = "10s.jpg"
images[11] = "11s.jpg"
var image = images[rand1]