/*
Flying Butterfly script (By BGAudioDr@aol.com)
Modified slightly/ permission granted to Dynamic Drive to feature script in archive
For full source, visit http://www.dynamicdrive.com
*/

var Ymax = 8;                                //MAX # OF PIXEL STEPS IN THE "X" DIRECTION
var Xmax = 8;                                //MAX # OF PIXEL STEPS IN THE "Y" DIRECTION
var Tmax = 10000;                        //MAX # OF MILLISECONDS BETWEEN PARAMETER CHANGES

//FLOATING IMAGE URLS FOR EACH IMAGE. ADD OR DELETE ENTRIES. KEEP ELEMENT NUMERICAL ORDER STARTING WITH "0" !!

var floatimages = new Array ();10
floatimages [0] = 'bilder/schmetterling1.gif';
floatimages [1] = 'bilder/schmetterling2.gif';
floatimages [2] = 'bilder/schmetterling3.gif';
floatimages [3] = 'bilder/schmetterling1.gif';
floatimages [4] = 'bilder/schmetterling2.gif';
floatimages [5] = 'bilder/schmetterling3.gif';
floatimages [6] = 'bilder/schmetterling1.gif';
floatimages [7] = 'bilder/schmetterling2.gif';
floatimages [8] = 'bilder/schmetterling3.gif';
floatimages [9] = 'bilder/schmetterling2.gif';
floatimages [10] = 'bilder/schmetterling3.gif';

//*** Browser identifizieren *********************************************************************************************
var NS4 = (navigator.appName.indexOf ("Netscape") >= 0 && parseFloat(navigator.appVersion) >= 4 && parseFloat(navigator.appVersion) < 5) ? true : false;
var IE4 = (document.all) ? true : false;
var NS6 = (parseFloat (navigator.appVersion) >= 5 && navigator.appName.indexOf ("Netscape") >= 0) ? true : false;
var wind_w, 
    wind_h, 
	t = '', 
	IDs = new Array ();

//*** Feld mit den Bildern durchlaufen und dem Browser entsprechendes HTML-erzeugen *************************************
for (i = 0; i < floatimages.length; i++)
{
  t += (NS4) ? '<layer name="pic' + i + '" visibility="hide" width="10" height="10"><a href="javascript:hidebutterfly()">' : '<div id="pic' + i + '" style="position:absolute; visibility:hidden;width:10px; height:10px"><a href="javascript:hidebutterfly ()">';
  t += '<img src="' + floatimages [i] + '" name="p' + i + '" border="0">';
  t += (NS4) ? '</a></layer>' : '</a></div>';
}
//*** Erzeugtes HTML in Dokument schreiben ******************************************************************************
document.write (t);

function moveimage (num)
{
  if (getidleft (num) + IDs [num].W + IDs [num].Xstep >= wind_w + getscrollx ())
    IDs [num].Xdir = false;
  if (getidleft(num) - IDs [num].Xstep <= getscrollx ()) 
    IDs [num].Xdir = true;
  if (getidtop(num) + IDs [num].H + IDs [num].Ystep >= wind_h + getscrolly ())
    IDs [num].Ydir = false;
  if (getidtop (num) - IDs [num].Ystep <= getscrolly ())
    IDs [num].Ydir = true;
  moveidby (num, (IDs [num].Xdir) ? IDs [num].Xstep : -IDs [num].Xstep , (IDs [num].Ydir) ? IDs [num].Ystep : -IDs [num].Ystep);
}

//*** neue Position des Bildes berechnen ********************************************************************************
function getnewprops (num)
{
  IDs [num].Ydir = Math.floor (Math.random () * 2) > 0;
  IDs [num].Xdir = Math.floor (Math.random () * 2) > 0;
  IDs [num].Ystep = Math.ceil (Math.random () * Ymax);
  IDs [num].Xstep = Math.ceil (Math.random () * Xmax);
  setTimeout ('getnewprops (' + num + ')', Math.floor (Math.random () * Tmax));
}

function getscrollx ()
{
  if (NS4 || NS6)
    return window.pageXOffset;
  if (IE4)
    return document.body.scrollLeft;
}

function getscrolly () 
{
  if (NS4 || NS6)
    return window.pageYOffset;
  if (IE4)
    return document.body.scrollTop;
}

function getid (name)
{
  if (NS4)
    return document.layers [name];
  if (IE4)
    return document.all [name];
  if (NS6)
    return document.getElementById (name);
}

function moveidto (num, x, y)
{
  if (NS4)
    IDs [num].moveTo (x, y);
  if (IE4 || NS6)
  {
    IDs [num].style.left = x + 'px';
    IDs [num].style.top = y + 'px';
  }
}

function getidleft (num)
{
  if (NS4)
    return IDs [num].left;
  if (IE4 || NS6)
    return parseInt (IDs [num].style.left);
}

function getidtop (num)
{
  if (NS4)
    return IDs [num].top;
  if (IE4 || NS6)
    return parseInt (IDs [num].style.top);
}

function moveidby (num, dx, dy)
{
  if (NS4) 
    IDs [num].moveBy (dx, dy);
  if (IE4 || NS6)
  {
    IDs [num].style.left = (getidleft (num) + dx) + 'px';
    IDs [num].style.top = (getidtop (num) + dy) + 'px';
  }
}

function getwindowwidth ()
{
  if (NS4 || NS6)
    return window.innerWidth;
  if (IE4)
    return document.body.clientWidth;
}

function getwindowheight()
{
  if(NS4 || NS6)
    return window.innerHeight;
  if (IE4)
    return document.body.clientHeight;
}

function init ()
{
  wind_w = getwindowwidth () - 20;
  wind_h = getwindowheight () - 50;
  for (i = 0; i < floatimages.length; i++)
  {
    IDs [i] = getid ('pic' + i);
    if (NS4)
	{
      IDs [i].W = IDs [i].document.images ["p" + i].width;
      IDs [i].H = IDs [i].document.images ["p" + i].height;
    }
    if(NS6 || IE4)
	{
      IDs [i].W = document.images ["p" + i].width;
      IDs [i].H = document.images ["p" + i].height;
    }
    getnewprops (i);
    moveidto (i , Math.floor (Math.random () * (wind_w-IDs [i].W)), Math.floor (Math.random () * (wind_h - IDs [i].H)));
    if (NS4)
	  IDs [i].visibility = "show";
    if (IE4 || NS6)
	  IDs [i].style.visibility = "visible";
    startfly = setInterval ('moveimage (' + i + ')', Math.floor (Math.random () * 100) + 100);
  }
}

function hidebutterfly ()
{
  for (i = 0; i < floatimages.length; i++)
  {
    if (IE4)
      eval ("document.all.pic" + i + ".style.visibility='hidden'")
    else if (NS6)
      document.getElementById ("pic" + i).style.visibility = 'hidden'
    else if (NS4)
      eval ("document.pic" + i + ".visibility='hide'")
    clearInterval (startfly)
  }
}

if (NS4||NS6||IE4)
{
  window.onload = init;
  window.onresize = function ()
  { 
    wind_w = getwindowwidth (); 
    wind_h = getwindowheight ();  
  }
}