//copied from http://pastelhorn.com/project/js/scrollspy/scrollspy-093.js.txt
var agt = navigator.userAgent.toLowerCase();
var isOpera = ( (agt.indexOf("opera") != -1)
                 && document.getElementById   ) ? 1 : 0;
                 

var isNav4 = (document.layers && !isOpera) ? 1 : 0;
var isIE4  = (document.all && !isOpera) ? 1 : 0;

var isMoz  = ( document.getElementById && !(isNav4 || isIE4 | isOpera) ) ? 1 : 0;

if (isNav4) {
  widthCheck = window.innerWidth;
  heightCheck = window.innerHeight;
  window.onResize = resizeFix;
}

function resizeFix() {
  if ( widthCheck != window.innerWidth || heightCheck != window.innerHeight )
    document.location.href = document.location.href;
} 

function getTop() {
layer = getDiv(scrollDiv);
  if (isNav4)
    return layer.top;
  else
    if (isIE4)
      return layer.style.pixelTop;
    else
	  if (isMoz) {
		return layer.style.top;
	  }
	  else
	    if (isOpera)          
		  return layer.style.top;
}


function setTop(layer, t) {
  if (isNav4)
    layer.top = t;
  else
    if (isIE4)
      layer.style.pixelTop = t;
    else
	  if (isMoz) {
	    var p = '' + t + 'px';
		layer.style.top = p;
	  }
	  else
	    if (isOpera)          
		  layer.style.top = t;
}

var divObject;

function getDiv(divname) {
	// given name 'divname', return div object
	// if div is within otherdiv, use 'otherdivname.divname' format as parameter

	divs = divname.split('.'); 

	if (isNav4) {
		s = ''
		for (i = 0; i < divs.length; i++) {
			s += 'document.layers.' + divs[i];
			if (i < divs.length - 1) 
				s += '.';
		}	
		divObject = eval(s);	
		return  divObject;
	}

	if (isIE4)
		divObject = eval( 'document.all.' + divs[ divs.length-1 ] );
		return divObject;

	if (isMoz || isOpera)
		divObject = document.getElementById(divs[ divs.length-1 ] );
		return divObject;

}


function update(scrollPos) {
  thediv = getDiv(scrollDiv);
  setTop(thediv, scrollPos+ origTop);
}

var S;

var scrollDiv;
var origTop;
  
function initSpy(tempScrollDiv) {  
  scrollDiv=tempScrollDiv;
   origTop = getTop(scrollDiv);
  S = new scrollSpy(update, tempScrollDiv);
  S.start();
}

function initSpyMult(tempScrollDiv, multName) {  
  scrollDiv=tempScrollDiv;
   origTop = getTop(scrollDiv);
  eval(multName + '= new scrollSpy(update, tempScrollDiv);');
  eval(multName + '.start()');
}


function scrollSpy(theFunction) {

//
// First, set window.RANDOMNAME to this Spy object, so the outside world
// can refer to it.
//
// Although ugly, it's needed, if we want "setInterval()" to apply a method
// on our object:  when using "setInterval("this...", ..)", the
// "this" will refer to the window, because that's the object running
// the function "setInterval".
//
// Another solution would be, passing the object's name as parameter to
// the constructor:
//
//   S = new scrollSpy('S', func)
//
// and use the first parameter to build the "setInterval()" command line.
//

  var NameOfThisSpy = generateSpyInternalName();
  
  eval('window.' + NameOfThisSpy + ' = this;'); // window.RANDOMNAME = <this_spy>
  eval('this.name = "' + NameOfThisSpy + '";'); // <this_spy>.name = "RANDOMNAME"

  this.changeFunction = theFunction;
  this.intervalTime = 200;   // by default 200 milliseconds
  this.enabled = 0;
  this.monitor = monitorScrolling;

  this.getWindowYOffset = getWindowYOffsetSpy;
  this.prevWindowYOffset = 0;

 /// public interface:  

  this.start = startSpy;
  this.stop = stopSpy;
  this.isRunning = isRunningSpy;
  
  this.getIntervalTime = getIntervalTimeSpy;
  this.setIntervalTime = setIntervalTimeSpy;

 /////
}



function startSpy() {
  if (!this.enabled) { // not already running?

    var cmdstring = 'window.' + this.name + '.monitor()';
    
    if (!isOpera)
      this.interval = window.setInterval( cmdstring, this.intervalTime );
    else // work around bug
      this.interval = window.setTimeout( cmdstring, this.intervalTime );

    this.enabled = 1;
  }
}

function stopSpy() {
  if (this.enabled) { // really running?
    window.clearInterval(this.interval);
    this.enabled = 0;
  }
}

function isRunningSpy() {
  return this.enabled;
}

    

function getIntervalTimeSpy() {
  return this.intervalTime;
}

function setIntervalTimeSpy(newValue) {
  var wasRunning = (this.enabled) ? 1 : 0;
  this.stop();
  this.intervalTime = newValue;
  if (wasRunning)
    this.start();
}



function getWindowYOffsetSpy() {

  if ( window.pageYOffset || window.pageYOffset == 0 )
    return window.pageYOffset;

  if ( document.body ) {
    if ( document.body.scrollTop || document.body.scrollTop == 0 ) {

      if ( document.documentElement ) {
        if ( document.documentElement.scrollTop || document.documentElement.scrollTop == 0 ) {
          // IE 6 uses document.documentElement.scrollTop instead of
          // document.body.scrollTop. Has to do with viewpoints -
          // see some w3 spec ;-)
          return document.body.scrollTop + document.documentElement.scrollTop; // +50;
        }

      } else {
        return document.body.scrollTop; // + 100;
      }
    }
  }
}
  
function monitorScrolling() {

  var newWinYOffset = getWindowYOffsetSpy();
  var Scrolled = (newWinYOffset != this.prevWindowYOffset);
//if (jdebug) alert(Scrolled);
  this.prevWindowYOffset = newWinYOffset;

  if (Scrolled) {
   
    eval( 'this.changeFunction(' + newWinYOffset + ')' );
    //if (jdebug) alert(newWinYOffset);
}

  if (isOpera) {  // work around bug
    var cmdstring = 'window.' + this.name + '.monitor()';
    this.interval = window.setTimeout( cmdstring, this.intervalTime);
  }
    
}



function generateSpyInternalName() {
  var now = new Date();
  var rand = Math.floor(  1000000 * Math.random(now.getTime())  );
  return ('spy' + rand + 's');
}