var clipTop = 0;
var clipWidth = 170;
var clipBottom = 400;
var topper = 30;
//var topper = 300;
var lyrheight = 0;
var time,amount,theTime,theHeight,DHTML;

function init()
{
	DHTML = (document.getElementById || document.all || document.layers);
	if (!DHTML) return;
	if (!document.mainnavigation) return;
	var x = new getObj('mainnavigation');
	if (!x) return;
	if (document.layers)
	{
		lyrheight = x.style.clip.bottom;
		lyrheight += 20;
		x.style.clip.top = clipTop;
		x.style.clip.left = 0;
		x.style.clip.right = clipWidth;
		x.style.clip.bottom = clipBottom;
	}
	else if (document.getElementById || document.all)
	{
		lyrheight = x.obj.offsetHeight;
		x.style.clip = 'rect('+clipTop+'px,'+clipWidth+'px,'+clipBottom+'px,0)';
	}
}

function scrollayer(layername,amt,tim)
{
	if (!DHTML) return;
	thelayer = new getObj(layername);
	if (!thelayer) return;
	amount = amt;
	theTime = tim;
	realscroll();
}

function realscroll()
{
	if (!DHTML) return;
	clipTop += amount;
	clipBottom += amount;
	topper -= amount;
	if (clipTop < 0 )
	{
		clipTop -= amount;
		clipBottom -= amount;
		topper += amount;
		return;
	}
	if (document.getElementById || document.all)
	{
		clipstring = 'rect('+clipTop+'px,'+clipWidth+'px,'+clipBottom+'px,0)';
		thelayer.style.clip = clipstring;
		thelayer.style.top = topper + 'px';
	}
	else if (document.layers)
	{
		thelayer.style.clip.top = clipTop;
		thelayer.style.clip.bottom = clipBottom;
		thelayer.style.top = topper;
	}
	time = setTimeout('realscroll()',theTime);
}

function stopScroll()
{
	if (time) clearTimeout(time);
}



function getObj(name)
{
  if (document.getElementById)
  {
	this.obj = document.getElementById(name);
	this.style = document.getElementById(name).style;
  }
  else if (document.all)
  {
	this.obj = document.all[name];
	this.style = document.all[name].style;
  }
  else if (document.layers)
  {
	this.obj = getObjNN4(document,name);
	this.style = this.obj;
  }
}

function getObjNN4(obj,name)
{
	var x = obj.layers;
	var foundLayer;
	for (var i=0;i<x.length;i++)
	{
		if (x[i].id == name)
		 	foundLayer = x[i];
		else if (x[i].layers.length)
			var tmp = getObjNN4(x[i],name);
		if (tmp) foundLayer = tmp;
	}
	return foundLayer;
}