if  ((document.getElementById) && 
window.addEventListener || window.attachEvent){

(function(){

var rm_img = new Image();
rm_img.src = "images/butterfly.gif"; 

var imgh = 163;  
var imgw = 156; 
var timer = 40; //setTimeout speed.
var min = 1;    //slowest speed.
var max = 2;    //fastest speed.

var idx = 1;
idx = parseInt(document.images.length);
if (document.getElementById("pic"+idx)) idx++;

var stuff = "<div id='pic"+idx+"' style='position:absolute;"
+"top:2px;left:2px;height:"+imgh+"px;width:"+imgw+"px;"
+"overflow:hidden'><img src='"+rm_img.src+"' alt=''/><\/div>";
document.write(stuff);

var h,w,r,temp;
var d = document;
var y = 800;
var x = 700;
var dir = 100;   //direction.
var acc = 3;    //acceleration.
var newacc = new Array(1,0,1);
var vel = 1;    //initial speed.
var sev = 0;
var newsev = new Array(1,-1,2,-2,0,0,1,-1,2,-2);

//counters.
var c1 = 0;    //time between changes.
var c2 = 0;    //new time between changes.

var pix = "px";
var domWw = (typeof window.innerWidth == "number");
var domSy = (typeof window.pageYOffset == "number");

if (domWw) r = window;
else{ 
  if (d.documentElement && 
  typeof d.documentElement.clientWidth == "number" && 
  d.documentElement.clientWidth != 0)
  r = d.documentElement;
 else{ 
  if (d.body && 
  typeof d.body.clientWidth == "number")
  r = d.body;
 }
}



function winsize(){
var oh,sy,ow,sx,rh,rw;
if (domWw){
  if (d.documentElement && d.defaultView && 
  typeof d.defaultView.scrollMaxY == "number"){
  oh = d.documentElement.offsetHeight;
  sy = d.defaultView.scrollMaxY;
  ow = d.documentElement.offsetWidth;
  sx = d.defaultView.scrollMaxX;
  rh = oh-sy;
  rw = ow-sx;
 }
 else{
  rh = r.innerHeight;
  rw = r.innerWidth;
 }
h = rh - imgh; 
w = rw - imgw;
}
else{
h = r.clientHeight - imgh; 
w = r.clientWidth - imgw;
}
}


function scrl(yx){
var y,x;
if (domSy){
 y = r.pageYOffset;
 x = r.pageXOffset;
 }
else{
 y = r.scrollTop;
 x = r.scrollLeft;
 }
return (yx == 0)?y:x;
}


function newpath(){
sev = newsev[Math.floor(Math.random()*newsev.length)];
acc = newacc[Math.floor(Math.random()*newacc.length)];
c2 = Math.floor(20+Math.random()*50);
}


function moveit(){
var vb,hb,dy,dx,curr;
if (acc == 1) vel +=0.05;
if (acc == 0) vel -=0.05;
if (vel >= max) vel = max;
if (vel <= min) vel = min;
c1++;
if (c1 >= c2){
 newpath();
 c1=0;
}
curr = dir+=sev;
dy = vel * Math.sin(curr*Math.PI/180);
dx = vel * Math.cos(curr*Math.PI/180);
y+=dy;
x+=dx;
//horizontal-vertical bounce.
vb = 180-dir;
hb = 0-dir;
//Corner rebounds?
if ((y < 1) && (x < 1)){y = 1; x = 1; dir = 45;}
if ((y < 1) && (x > w)){y = 1; x = w; dir = 135;}
if ((y > h) && (x < 1)){y = h; x = 1; dir = 315;}
if ((y > h) && (x > w)){y = h; x = w; dir = 225;}
//edge rebounds.
if (y < 1) {y = 1; dir = hb;}  
if (y > h) {y = h; dir = hb;}  
if (x < 1) {x = 1; dir = vb;} 
if (x > w) {x = w; dir = vb;} 

//Assign it all to image.
temp.style.top = y + scrl(0) + pix;
temp.style.left = x + scrl(1) + pix;
setTimeout(moveit,timer);
}

function init(){
temp = document.getElementById("pic"+idx);
winsize();
moveit();
}


if (window.addEventListener){
 window.addEventListener("resize",winsize,false);
 window.addEventListener("load",init,false);
}  
else if (window.attachEvent){
 window.attachEvent("onresize",winsize);
 window.attachEvent("onload",init);
} 

})();
}//End.