var browser = {
	init: function () {
		this.browser = this.searchString(this.dataBrowser) || "An unknown browser";
		this.version = this.searchVersion(navigator.userAgent)
			|| this.searchVersion(navigator.appVersion)
			|| "an unknown version";
		this.OS = this.searchString(this.dataOS) || "an unknown OS";
	},
	searchString: function (data) {
		for (var i=0;i<data.length;i++)	{
			var dataString = data[i].string;
			var dataProp = data[i].prop;
			this.versionSearchString = data[i].versionSearch || data[i].identity;
			if (dataString) {
				if (dataString.indexOf(data[i].subString) != -1)
					return data[i].identity;
			}
			else if (dataProp)
				return data[i].identity;
		}
	},
	searchVersion: function (dataString) {
		var index = dataString.indexOf(this.versionSearchString);
		if (index == -1) return;
		return parseFloat(dataString.substring(index+this.versionSearchString.length+1));
	},
	dataBrowser: [
		{ String: navigator.userAgent,
			subString: "OmniWeb",
			versionSearch: "OmniWeb/",
			identity: "OmniWeb"
		},
		{
			string: navigator.vendor,
			subString: "Apple",
			versionSearch: "Version",
			identity: "Safari"
		},
		{
			prop: window.opera,
			identity: "Opera"
		},
		{
			string: navigator.vendor,
			subString: "iCab",
			identity: "iCab"
		},
		{
			string: navigator.vendor,
			subString: "KDE",
			identity: "Konqueror"
		},
		{
			string: navigator.userAgent,
			subString: "Firefox",
			identity: "Firefox"
		},
		{
			string: navigator.vendor,
			subString: "Camino",
			identity: "Camino"
		},
		{		// for newer Netscapes (6+)
			string: navigator.userAgent,
			subString: "Netscape",
			identity: "Netscape"
		},
		{
			string: navigator.userAgent,
			subString: "MSIE",
			identity: "Explorer",
			versionSearch: "MSIE"
		},
		{
			string: navigator.userAgent,
			subString: "Gecko",
			identity: "Mozilla",
			versionSearch: "rv"
		},
		{ 		// for older Netscapes (4-)
			string: navigator.userAgent,
			subString: "Mozilla",
			identity: "Netscape",
			versionSearch: "Mozilla"
		}
	],
	dataOS : [
		{
			string: navigator.platform,
			subString: "Win",
			identity: "Windows"
		},
		{
			string: navigator.platform,
			subString: "Mac",
			identity: "Mac"
		},
		{
			string: navigator.platform,
			subString: "Linux",
			identity: "Linux"
		}
	]

};
browser.init();

var browserCompatible = function() {
	var compatible = {
		browser: [ 'Firefox', 'Explorer', 'Opera'/*, 'Safari'*/ ],
		version: {
			Firefox: 1.5,
			Explorer: 5.5,
			Opera: 8/*,
			Safari: 2*/
		},
		os: {
			Windows: {
				re: 'Windows NT (\\d)',
				version: 5
			},
			Mac: {
				re: 'Mac OS X'
			}
		}
	};
	
	var agent = false;
	for (i in compatible.browser) {
		if (compatible.browser[i] == browser.browser && browser.version >= compatible.version[browser.browser]) agent = true;
	}
	
	os = false;
	var re = new RegExp(compatible.os[browser.OS].re, "i");
	var match = re.exec(navigator.oscpu || navigator.userAgent);
	
	if (match != null) {
		if (compatible.os[browser.OS].version && typeof(match[1]) != 'undefined') {
			var version = parseFloat(match[1]);
			os = version >= compatible.os[browser.OS].version;
		} else {
			os = true;
		}
	}
	
	if (agent == true && os == true) return 0; // ok
	else if (agent == false && os == true) return 1; // incompatible browser
	else if (agent == true && os == false) return 2; // incompatible os
	else return 3; // incompatible both
};

var hasClass = function(elem, klass) {
	var r = new RegExp("(^|\\s)" + klass + "(\\s|$)");
	return r.test(elem.className);
};

var addClass = function(elem, klass) {
	if (!this.hasClass(elem, klass)) {
		elem.className += (elem.className ? " " : "") + klass;
		return elem;
	}
};

var removeClass = function(elem, klass) {
	var r = new RegExp("(^|\\s)" + klass + "(\\s|$)");
	elem.className = elem.className.replace(r, "$2");
	return elem;
};