var nDots = 3;
var Xpos = 10;
var Ypos = 10;
var DELTAT = .01;
var SEGLEN = 15;
var SPRINGK = 10;
var MASS = 1;
var GRAVITY = 40;
var RESISTANCE = 20;
var STOPVEL = 0.1;
var STOPACC = 0.1;
var DOTSIZE = 32;
var BOUNCE = 0.75;
var isNetscape = navigator.appName == "Netscape";
var followmouse = true;
var dots = new Array ();
init ();
function
init ()
{
  var i = 0;
  for (i = 0; i < nDots; i++)
    {
      dots[i] = new dot (i);
    }
  if (!isNetscape)
    {
    }
  for (i = 0; i < nDots; i++)
    {
      dots[i].obj.left = dots[i].X;
      dots[i].obj.top = dots[i].Y;
    }
  if (isNetscape)
    {
      startanimate ();
    }
  else
    {
      setTimeout ("startanimate()", 0);
    }
}
function
dot (i)
{
  this.X = Xpos;
  this.Y = Ypos;
  this.dx = 0;
  this.dy = 0;
  if (isNetscape)
    {
      this.obj = eval ("document.dot" + i);
    }
  else
    {
      this.obj = eval ("dot" + i + ".style");
    }
}
function
startanimate ()
{
  setInterval ("animate()", 20);
}

function
setInitPositions (dots)
{
  var startloc = document.all.tags ("LI");
  var i = 0;
  for (i = 0; i < startloc.length && i < (nDots - 1); i++)
    {
      dots[i + 1].X =
	startloc[i].offsetLeftstartloc[i].offsetParent.offsetLeft - DOTSIZE;
      dots[i + 1].Y =
	startloc[i].offsetTop + startloc[i].offsetParent.offsetTop +
	2 * DOTSIZE;
    }
  dots[0].X = dots[1].X;
  dots[0].Y = dots[1].Y - SEGLEN;
}

function
MoveHandler (e)
{
  Xpos = e.pageX;
  Ypos = e.pageY;
  return true;
}

function
MoveHandlerIE ()
{
  Xpos = window.event.x + document.body.scrollLeft;
  Ypos = window.event.y + document.body.scrollTop;
}

if (isNetscape)
  {
    document.captureEvents (Event.MOUSEMOVE);
    document.onMouseMove = MoveHandler;
  }
else
  {
    document.onmousemove = MoveHandlerIE;
  }

function
vec (X, Y)
{
  this.X = X;
  this.Y = Y;
}

function
springForce (i, j, spring)
{
  var dx = (dots[i].X - dots[j].X);
  var dy = (dots[i].Y - dots[j].Y);
  var len = Math.sqrt (dx * dx + dy * dy);
  if (len > SEGLEN)
    {
      var springF = SPRINGK * (len - SEGLEN);
      spring.X += (dx / len) * springF;
      spring.Y += (dy / len) * springF;
    }
}
function
animate ()
{
  var start = 0;
  if (followmouse)
    {
      dots[0].X = Xpos;
      dots[0].Y = Ypos;
      start = 1;
    }
  for (i = start; i < nDots; i++)
    {
      var spring = new vec (0, 0);
      if (i > 0)
	{
	  springForce (i - 1, i, spring);
	}
      if (i < (nDots - 1))
	{
	  springForce (i + 1, i, spring);
	}
      var resist =
	new vec (-dots[i].dx * RESISTANCE, -dots[i].dy * RESISTANCE);
      var accel =
	new vec ((spring.X + resist.X) / MASS,
		 (spring.Y + resist.Y) / MASS + GRAVITY);
      dots[i].dx += (DELTAT * accel.X);
      dots[i].dy += (DELTAT * accel.Y);
      if (Math.abs (dots[i].dx) < STOPVEL && Math.abs (dots[i].dy) < STOPVEL
	  && Math.abs (accel.X) < STOPACC && Math.abs (accel.Y) < STOPACC)
	{
	  dots[i].dx = 0;
	  dots[i].dy = 0;
	}
      dots[i].X += dots[i].dx;
      dots[i].Y += dots[i].dy;
      var height, width;
      if (isNetscape)
	{
	  height = window.innerHeight + document.scrollTop;
	  width = window.innerWidth + document.scrollLeft;
	}
      else
	{
	  height = document.body.clientHeight + document.body.scrollTop;
	  width = document.body.clientWidth + document.body.scrollLeft;
	}
      if (dots[i].Y >= height - DOTSIZE - 1)
	{
	  if (dots[i].dy > 0)
	    {
	      dots[i].dy = BOUNCE * -dots[i].dy;
	    }
	  dots[i].Y = height - DOTSIZE - 1;
	}
      if (dots[i].X >= width - DOTSIZE)
	{
	  if (dots[i].dx > 0)
	    {
	      dots[i].dx = BOUNCE * -dots[i].dx;
	    }
	  dots[i].X = width - DOTSIZE - 1;
	}
      if (dots[i].X < 0)
	{
	  if (dots[i].dx < 0)
	    {
	      dots[i].dx = BOUNCE * -dots[i].dx;
	    }
	  dots[i].X = 0;
	}
      dots[i].obj.left = dots[i].X;
      dots[i].obj.top = dots[i].Y;
    }
}