var imagenumber = 4;
var randomnumber = Math.random();
var rand1 = Math.round( (imagenumber-1) * randomnumber) + 1;
images = new Array;
images[1] = 
  "images/rotate1.jpg"
  
images[2] = 
  "images/rotate2.jpg"
  
images[3] = 
  "images/rotate3.jpg"
  
images[4] = 
  "images/rotate4.jpg"
  

var image1 = images[rand1];

<!--

function tmt_findObj(n){
	var x,t; if((n.indexOf("?"))>0&&parent.frames.length){t=n.split("?");
	x=eval("parent.frames['"+t[1]+"'].document.getElementById('"+t[0]+"')");
	}else{x=document.getElementById(n)}return x;
}
//-->