var Mac = (navigator.appVersion.indexOf("Macintosh") != -1);
var IE  = (navigator.appVersion.indexOf("MSIE") != -1) && !(navigator.userAgent.indexOf("Opera") != -1);

function pageScrollToTop() {
	pageScrollTo(0);
}

function pageScrollToObj( id ) {
	var y = _v_GetObjPosY(id);
	
	pageScrollTo( y );
}

function pageScrollTo( y ) {

	var w = window;
	var d = document.documentElement;
	var b = document.body;
	var mac = Mac && IE;
	
	var windowH = (w.innerHeight) ? w.innerHeight : (!mac) ? d.offsetHeight : b.scrollHeight;
	var pageH   = (!mac) ? b.scrollHeight : d.offsetHeight;
	var maxY    = (pageH > windowH) ? pageH - windowH : 0;

	if( _v_scrollTimer ) clearInterval( _v_scrollTimer );
	
	_v_scrollToY = y < maxY ? y : maxY;
	_v_scrollLastY = _v_GetScrollPosY();
	_v_scrollTimer = setInterval( '_v_ScrollDo();', 16 );
}

var _v_scrollToY;
var _v_scrollLastY;
var _v_scrollTimer;

function _v_ScrollDo() {
	var d = _v_scrollLastY - _v_scrollToY;
	var done = false;
	if( Math.abs(d)<1 ) {
		done = true;
		_v_scrollLastY = _v_scrollToY;
	} else if( _v_GetScrollPosY() != Math.floor(_v_scrollLastY) ) done = true;
	else _v_scrollLastY -= d / 10;
	self.scrollTo( 0, Math.floor(_v_scrollLastY) );
	if( done ) {
		clearInterval( _v_scrollTimer );
		_v_scrollTimer = null;
	}
}

function _v_GetScrollPosY() {
	var w = window;
	var d = document.documentElement;
	var b = document.body;
	return (w.scrollY) ? w.scrollY : (d.scrollTop) ? d.scrollTop  : b.scrollTop;
}

function _v_GetObjPosY( id ) {
	var o = vGetObj(id);
	if( document.getElementById ) return o.offsetTop;
	if( IE ) return o.style.pixelTop;
	return o.top;
}