var imagenumber = 2 ;
var randomnumber = Math.random() ;
var rand1 = Math.round( (imagenumber-1) * randomnumber) + 1 ;
images = new Array
images[1] = "dido197.jpg"
images[2] = "dido198.jpg"
var myimage = images[rand1]
document.write('<IMG src="' + myimage + '" alt="Dido" width=222 height=280>')