function Browser() {
	var ua, s, i;
	this.isIE    = false;
	this.isNS    = false;
	this.version = null;
	ua = navigator.userAgent;
	s = "MSIE";
	if ((i = ua.indexOf(s)) >= 0) {
		this.isIE = true;
		this.version = parseFloat(ua.substr(i + s.length));
		return;
	}
	s = "Netscape6/";
	if ((i = ua.indexOf(s)) >= 0) {
		this.isNS = true;
		this.version = parseFloat(ua.substr(i + s.length));
		return;
	}
	s = "Gecko";
	if ((i = ua.indexOf(s)) >= 0) {
		this.isNS = true;
		this.version = 6.1;
		return;
	}
} 
var browser = new Browser();

function getViewportWidth() {
	var width = 0;
	if( document.documentElement && document.documentElement.clientWidth ) {
		width = document.documentElement.clientWidth;
	}
	else if( document.body && document.body.clientWidth ) {
		width = document.body.clientWidth;
	}
	else if( window.innerWidth ) {
		width = window.innerWidth - 18;
	}
	return width;
}

function getViewportHeight() {
	var height = 0;
	if( document.documentElement && document.documentElement.clientHeight ) {
		height = document.documentElement.clientHeight;
	}
	else if( document.body && document.body.clientHeight ) {
		height = document.body.clientHeight;
	}
	else if( window.innerHeight ) {
		height = window.innerHeight - 18;
	}
	return height;
}
   
function getViewportScrollX() {
	var scrollX = 0;
	if( document.documentElement && document.documentElement.scrollLeft ) {
		scrollX = document.documentElement.scrollLeft;
	}
	else if( document.body && document.body.scrollLeft ) {
		scrollX = document.body.scrollLeft;
	}
	else if( window.pageXOffset ) {
		scrollX = window.pageXOffset;
	}
	else if( window.scrollX ) {
		scrollX = window.scrollX;
	}
	return scrollX;
}

function getViewportScrollY() {
	var scrollY = 0;
	if( document.documentElement && document.documentElement.scrollTop ) {
		scrollY = document.documentElement.scrollTop;
	}
	else if( document.body && document.body.scrollTop ) {
		scrollY = document.body.scrollTop;
	}
	else if( window.pageYOffset ) {
		scrollY = window.pageYOffset;
	}
	else if( window.scrollY ) {
		scrollY = window.scrollY;
	}
	return scrollY;
}