var imagenumber = 5 ; 
var randomnumber = Math.random() ; 
var rand1 = Math.round( (imagenumber-1) * randomnumber) + 1 ; 
images = new Array 
images[1] = "public/destro1.gif" 
images[2] = "public/destro2.gif"
images[3] = "public/destro3.gif"
images[4] = "public/destro4.gif"
images[5] = "public/destro5.gif"
var myimage = images[rand1] 
document.write('<img src="' + myimage + '",  width="120" height="340" alt="Show" border="0" />')