var oChaser = {
	callRate	: 10,
	slideTime	: 1200,
	maxDiff		: document.all ? document.body.clientHeight : window.innerHeight,
	isIE		: document.all ? true : false,
	chaserDiv	: document[document.all ? "all" : "layers"]["LeftButtons"]
}

window.setInterval("oChaser.main( )", oChaser.callRate)

oChaser.main = function( )
{
	this.currentY			= this.isIE ? this.chaserDiv.style.pixelTop : this.chaserDiv.top
	this.scrollTop			= this.isIE ? document.body.scrollTop : window.pageYOffset
	this.scrollHeight		= this.isIE ? document.body.scrollHeight : window.outerHeight
	this.availSpace			= this.scrollHeight - this.scrollTop
	this.midpoint			= this.scrollHeight / 2
	
	var maxY				= this.chaserDiv.parentNode.offsetHeight - this.chaserDiv.offsetHeight - 60;
	if(maxY < 0) maxY = 0;

	
	if ((this.maxDiff/4) > this.scrollTop) {
		var newTargetY		= 0;
	}
	else {
		if (this.availSpace > this.midpoint){
			var newTargetY		= this.scrollTop + ((1/5)*this.maxDiff)
		}
		else if (this.availSpace < this.midpoint){
			var newTargetY		= (this.scrollHeight - (this.availSpace)) + ((1/3) * this.maxDiff)
		}

		if(newTargetY > maxY)
		{
			newTargetY = maxY;
		}
	}
	
	if ( this.currentY != newTargetY ) {
		if ( newTargetY != this.targetY ) {
			this.targetY = newTargetY
			this.slideInit( )
		}
		this.slide( )
	}
}

oChaser.slideInit = function( )
{
	var now	= new Date( )

	this.A		= this.targetY - this.currentY
	this.B		= Math.PI / ( 2 * this.slideTime )
	this.C		= now.getTime( )

	if (Math.abs(this.A) > this.maxDiff) {
		this.D = this.A > 0 ? this.targetY - this.maxDiff : this.targetY + this.maxDiff
		this.A = this.A > 0 ? this.maxDiff : -this.maxDiff
	} else {
		this.D = this.currentY
	}
}

oChaser.slide = function( )
{
	var now	= new Date( )
	var newY	= this.A * Math.sin( this.B * ( now.getTime( ) - this.C ) ) + this.D
	newY		= Math.round( newY )

	if (( this.A > 0 && newY > this.currentY ) ||
		( this.A < 0 && newY < this.currentY )) {
			
			if ( this.isIE )this.chaserDiv.style.pixelTop = newY;
			else			this.chaserDiv.top = newY
	}
}