var idup=0;
var iddown=0;
var heightup=0;
var posYinner=0;
var posYfinal=0;

function initBox(){
	var bi=$('boxinner');
	if(bi) {
		bi.style.top=0+"px";
		posYinner=findY(bi);
	}

	var b=$('boxris');
	if(b){
		heightup=b.offsetHeight;
	}

	var bf=$('boxfinale');
	if(bf){
		posYfinal=findY(bf);
		heightup=-((posYfinal-posYinner)-heightup);
	}
}

function scrollUp(){
	clearInterval(iddown);
	iddown=0;
	if(idup==0)
		idup=setInterval("scrollUpInterval(10)", 75);
	else {
		clearInterval(idup);
		idup=0;
	}
}
function scrollDown(){
	clearInterval(idup);
	idup=0;
	if(iddown==0)
		iddown=setInterval("scrollDownInterval(10)", 75);
	else {
		clearInterval(iddown);
		iddown=0;
	}
}

function scrollUpInterval(px){
	var obj=$('boxinner');
	if(obj && parseInt(obj.style.top,10)<0){
		obj.style.top=parseInt(obj.style.top,10)+parseInt(px,10)+"px";
	}else {
		clearInterval(idup);
		idup=0;
	}
}
function scrollDownInterval(px){
	var obj=$('boxinner');
	if(obj && parseInt(obj.style.top,10)>heightup) {
		obj.style.top=parseInt(obj.style.top,10)-parseInt(px,10)+"px";
	}else{
		clearInterval(iddown);
		iddown=0;
	}
}