var scrollspeed = 1;
var scroll = 0;
var h, wh, maxheight, way, timer;

function GetHeight(){
	if(document.all){
		h  = window.frames["iframe1"].document.body.scrollHeight;
		wh = document.all.iframe1.offsetHeight;
		window.frames["iframe1"].scrollTo(0,0);
	}else if(document.layers){
		h  = document.layers["parentLay"].layers["scrollLay"].document.height;
		wh = document.layers["parentLay"].clip.height;
	}
	if(document.all || document.layers){
		maxheight = h - wh;
	}
}

function StartScroll(y){
	if(!(document.all || document.layers)){return;}
	way = y>0 ? 1:0;
	if((scroll < maxheight && way) || (scroll > 0 && !way)){
		scroll += y;
		if(document.all){
			window.frames["iframe1"].scrollTo(0, scroll);
		}else if(document.layers){
			document.layers["parentLay"].layers["scrollLay"].top = -scroll;
		}
		timer = setTimeout("StartScroll("+y+")", scrollspeed);
	}
}

function StopScroll(){
	if(timer && (document.all || document.layers)){
		clearTimeout(timer);
	}
}
window.onload = GetHeight;