var imagenumber = 16 ; 
var randomnumber = Math.random() ; 
var rand1 = Math.round( (imagenumber-1) * randomnumber) + 1 ; 
images = new Array 
images[1] = "startseite_01.jpg" 
images[2] = "startseite_02.jpg"
images[3] = "startseite_03.jpg" 
images[4] = "startseite_04.jpg"
images[5] = "startseite_05.jpg" 
images[6] = "startseite_06.jpg"
images[7] = "startseite_07.jpg" 
images[8] = "startseite_08.jpg" 
images[9] = "startseite_09.jpg" 
images[10] = "startseite_10.jpg" 
images[11] = "startseite_11.jpg" 
images[12] = "startseite_12.jpg" 
images[13] = "startseite_13.jpg" 
images[14] = "startseite_14.jpg" 
images[15] = "startseite_15.jpg" 
images[16] = "startseite_16.jpg"
var image = images[rand1]