Random image bij klikken

<script language="JavaScript" type="text/JavaScript">
<!--
var theImages = new Array()

theImages[0] = 'images/layout/foto1.jpg'
theImages[1] = 'images/layout/foto2.jpg'
theImages[2] = 'images/layout/foto3.jpg'

var j = 0
var p = theImages.length;
var preBuffer = new Array()
for (i = 0; i < p; i++){
   preBuffer[i] = new Image()
   preBuffer[i].src = theImages[i]
}
var whichImage = Math.round(Math.random()*(p-1));

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_setTextOfLayer(objName,x,newText) { //v4.01
  if ((obj=MM_findObj(objName))!=null) with (obj)
    if (document.layers) {document.write(unescape('<img src="'+theImages[whichImage]+'">')); document.close();}
    else innerHTML = unescape('<img src="'+theImages[whichImage]+'">');
}

//-->
</script>

<script language="JavaScript" type="text/JavaScript">
<!--
var theImages = new Array()
 
theImages[0] = 'images/layout/foto1.jpg'
theImages[1] = 'images/layout/foto2.jpg'
theImages[2] = 'images/layout/foto3.jpg'
 
var j = 0
var p = theImages.length;
var preBuffer = new Array()
for (i = 0; i < p; i++){
   preBuffer[i] = new Image()
   preBuffer[i].src = theImages[i]
}
var whichImage = Math.round(Math.random()*(p-1));
 
function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}
 
function MM_setTextOfLayer(objName,x,newText) { //v4.01
  if ((obj=MM_findObj(objName))!=null) with (obj)
    if (document.layers) {document.write(unescape('<img src="'+theImages[whichImage]+'">')); document.close();}
    else innerHTML = unescape('<img src="'+theImages[whichImage]+'">');
}
 
//-->
</script>

onClick="MM_setTextOfLayer('main','')"

onClick="MM_setTextOfLayer('main','')"