var t;
var vMaxAltura = 0;
var vMaxBar = 194;



function dragged(event)
{
	vArg1 = $A(arguments)[1];
	vArg2 = $A(arguments)[2];

	vObj = $("scrollball");
	vDIV = $("conteudo-principal");


	vPosition = parseInt( Event.pointerY(event) - vArg1 + vArg2 );

	if( vPosition <= 0 )
	{
		vPosition = 0;
		vDIV.scrollTop = 0;	
	}else if( vPosition >= vMaxBar )
	{
		vPosition = vMaxBar;
		vDIV.scrollTop = vMaxAltura;	
	}else
	{
		vScroll = ( vMaxAltura * vPosition )/vMaxBar;
		vDIV.scrollTop = Math.round( vScroll );
	}
	
	vObj.style.top = vPosition + "px"
}

function configScroll()
{
	vDIV = $("conteudo-principal");

	vMaxAltura = parseInt(vDIV.scrollHeight - 411);

	if( vMaxAltura  <= 0 )
		{$("scrolldiv").style.display = "none"}
	else {
		updateScroller();
		vObj = $("scrollball");
		vObj.observe( 'mousedown' , startdrag );
	}


}

function startdrag(event)
{
	vObj = $("scrollball");
	listener = dragged.bindAsEventListener(vObj , Event.pointerY(event) , parseInt(vObj.style.top) ) ;
	Event.observe( document , 'mousemove' , listener )
	//Event.observe( vObj , 'mousemove' , listener )
	document.observe( 'mouseup' , stopdrag );
}


function stopdrag()
{
	Event.stopObserving( document , 'mousemove' , listener )
	Event.stopObserving( document ,'mouseup' , stopdrag );
	//Event.stopObserving( vObj , 'mousemove' , listener )

}
function scrollUP() {

	vDIV = $("conteudo-principal");
	vAlturaAtual = vDIV.scrollTop;


	if( vAlturaAtual >= vMaxAltura )
	{
		stopScroll();
	}else	{
		vDIV.scrollTop = vDIV.scrollTop + 1;
		updateScroller();
		t = setTimeout( "scrollUP()" , 2 );
	}

}

function updateScroller()
{
	vDIV = $("conteudo-principal");
	vAlturaAtual = vDIV.scrollTop;

	if( vAlturaAtual == 0 )
		{$("scrollball").style.top = 0;}
	else {

		vPosition = parseInt((vAlturaAtual * vMaxBar) / vMaxAltura);
		if( vPosition < 0 )
			{vPosition = 0}
		else if( vPosition > vMaxBar )
			{vPosition = vMaxBar}
		$("scrollball").style.top = Math.round(vPosition) + "px";
	}
}

function scrollDOWN() {
	vDIV = $("conteudo-principal");
	vAlturaAtual = vDIV.scrollTop;


	if( vAlturaAtual <= 0 )
	{
		stopScroll();
	}else	{
		vDIV.scrollTop = vDIV.scrollTop  - 1 ;
		updateScroller();
		t = setTimeout( "scrollDOWN()" , 2 );
	}
}


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