function doScrollEffect(id, vspeed) {
	var scrollId = id;
	var scrollVspeed = vspeed;
	if (scrollId) {
		var div = document.getElementById(scrollId);
		div.scrollTop=Math.max(0, Math.min(div.scrollHeight-div.clientHeight, div.scrollTop+scrollVspeed));
	}
	return false;
}
var scrollInterval;
function startScrollBlok(id, vspeed) {
	if (id && document.getElementById(id)) {
		clearInterval(scrollInterval);
		var div = document.getElementById(id);
		doScrollBlok(div, vspeed);
		scrollInterval = setInterval( function() { doScrollBlok(div, vspeed); }, 50 )
	}
}

function stopScrollBlok() {
	clearInterval(scrollInterval);
}

function doScrollBlok(element, vspeed) {
	element.scrollTop=Math.max(0, Math.min(element.scrollHeight-element.clientHeight, element.scrollTop+vspeed));
}