var Base64 = {

    // private property
    _keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",

    // public method for encoding
    encode : function (input) {
        var output = "";
        var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
        var i = 0;

        input = Base64._utf8_encode(input);

        while (i < input.length) {

            chr1 = input.charCodeAt(i++);
            chr2 = input.charCodeAt(i++);
            chr3 = input.charCodeAt(i++);

            enc1 = chr1 >> 2;
            enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
            enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
            enc4 = chr3 & 63;

            if (isNaN(chr2)) {
                enc3 = enc4 = 64;
            } else if (isNaN(chr3)) {
                enc4 = 64;
            }

            output = output +
            this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
            this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4);

        }

        return output;
    },

    // public method for decoding
    decode : function (input) {
        var output = "";
        var chr1, chr2, chr3;
        var enc1, enc2, enc3, enc4;
        var i = 0;

        input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

        while (i < input.length) {

            enc1 = this._keyStr.indexOf(input.charAt(i++));
            enc2 = this._keyStr.indexOf(input.charAt(i++));
            enc3 = this._keyStr.indexOf(input.charAt(i++));
            enc4 = this._keyStr.indexOf(input.charAt(i++));

            chr1 = (enc1 << 2) | (enc2 >> 4);
            chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
            chr3 = ((enc3 & 3) << 6) | enc4;

            output = output + String.fromCharCode(chr1);

            if (enc3 != 64) {
                output = output + String.fromCharCode(chr2);
            }
            if (enc4 != 64) {
                output = output + String.fromCharCode(chr3);
            }

        }

        output = Base64._utf8_decode(output);

        return output;

    },

    // private method for UTF-8 encoding
    _utf8_encode : function (string) {
        string = string.replace(/\r\n/g,"\n");
        var utftext = "";

        for (var n = 0; n < string.length; n++) {

            var c = string.charCodeAt(n);

            if (c < 128) {
                utftext += String.fromCharCode(c);
            }
            else if((c > 127) && (c < 2048)) {
                utftext += String.fromCharCode((c >> 6) | 192);
                utftext += String.fromCharCode((c & 63) | 128);
            }
            else {
                utftext += String.fromCharCode((c >> 12) | 224);
                utftext += String.fromCharCode(((c >> 6) & 63) | 128);
                utftext += String.fromCharCode((c & 63) | 128);
            }

        }

        return utftext;
    },

    // private method for UTF-8 decoding
    _utf8_decode : function (utftext) {
        var string = "";
        var i = 0;
        var c = c1 = c2 = 0;

        while ( i < utftext.length ) {

            c = utftext.charCodeAt(i);

            if (c < 128) {
                string += String.fromCharCode(c);
                i++;
            }
            else if((c > 191) && (c < 224)) {
                c2 = utftext.charCodeAt(i+1);
                string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
                i += 2;
            }
            else {
                c2 = utftext.charCodeAt(i+1);
                c3 = utftext.charCodeAt(i+2);
                string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
                i += 3;
            }

        }

        return string;
    }

}

request = {
	xml : function(url,callback) {
		var tr = this.acquire();
		if (!tr) {
			setTimeout(function() { request.xml(url, callback); }, 100);
			return;
		}
		tr.onreadystatechange = function() {
			if (tr.readyState!=4) return;
			if (tr.status!=200) return;
			if (callback && tr.responseXML)
				callback(tr.responseXML);
			request.release(tr);
		}
		tr.open("GET", this.randomize(url), true);
		tr.send("");
	},
	html : function(url,callback) {
		var tr = this.acquire();
		if (!tr) {
			setTimeout(function() { request.html(url, callback); }, 100);
			return;
		}
		tr.onreadystatechange = function() {
			if (tr.readyState!=4) return;
			if (tr.status!=200) return;
			if (callback && tr.responseText)
				callback(tr.responseText);
			request.release(tr);
		}
		tr.open("GET", this.randomize(url), true);
		tr.send("");
	},
	htmlnow : function(url) {
		var tr = this.acquire();
		tr.onreadystatechange = function() { };
		tr.open("GET", this.randomize(url), false);
		tr.send("");
		if (tr.readyState!=4) return "";
		if (tr.status!=200) return "";
		var rs = tr.responseText;
		request.release(tr);
		return rs;
	},
	json : function(url,callback) {
		var tr = this.acquire();
		if (!tr) {
			setTimeout(function() { request.json(url, callback); }, 100);
			return;
		}
		tr.onreadystatechange = function() {
			if (tr.readyState!=4) return;
			if (tr.status!=200) /*{ alert("url: "+tr.status); */return; /*}*/
			if (callback && tr.responseText) {
				var rs = null;
				try {
					rs = eval("("+tr.responseText+")");
				} catch (e) {
					alert("Error in server return:\n\n"+tr.responseText);
					rs = null;
				}
				callback(rs);
			} else if (callback)
				callback({});
			request.release(tr);
		}
		tr.open("GET", this.randomize(url), true);
		tr.send("");
	},
	jsonnow : function(url) {
		var tr = this.acquire();
		tr.onreadystatechange = function() { };
		tr.open("GET", this.randomize(url), false);
		tr.send("");
		if (tr.readyState!=4) return { };
		if (tr.status!=200) return { };
		var rs = { };
		if (tr.responseText) {
			try {
				rs = eval("("+tr.responseText+")");
			} catch (e) {
				alert("Error in server return:\n\n"+tr.responseText);
				rs = { };
			}
		} else
			rs = { };
		request.release(tr);
		return rs;
	},
	post : function(url,vars,callback) {
		var body = "";
		for (var a in vars)
			if (vars[a]!=null && typeof vars[a]!="function")
				body += (body?"&":"")+a+"="+vars[a];
		var tr = this.acquire();
		if (!tr) {
			setTimeout(function() { request.post(url, vars, callback); }, 100);
			return;
		}
		tr.onreadystatechange = function() {
			if (tr.readyState!=4) return;
			if (tr.status!=200) return;
			if (callback && tr.responseText) {
				var rs = null;
				try {
					rs = eval("("+tr.responseText+")");
				} catch (e) {
					alert("Error in server return:\n\n"+tr.responseText);
					rs = null;
				}
				callback(rs);
			}
			request.release(tr);
		}
		tr.open("POST", this.randomize(url), true);
		tr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
		tr.send(body);
	},
	randomize : function(url) {
		if (url.indexOf("?")>=0)
			url += "&"+Math.random();
		else
			url += "?"+Math.random();
		return url;
	},
	rqcache : [],
	rqfree : [],
	transport : function() {
		if (window.XMLHttpRequest)
			return new XMLHttpRequest();
		else if (window.ActiveXObject)
			return new ActiveXObject('Microsoft.XMLHTTP');
		else
			return null;
	},
	acquire : function() {
		for (var i=0; i<this.rqcache.length; i++)
			if (this.rqfree[i]) {
				this.rqfree[i] = false;
				return this.rqcache[i];
			}
		return null;
	},
	release : function(r) {
		r.abort();
		r.onreadystatechange = function() { };
		for (var i=0; i<this.rqcache.length; i++)
			if (this.rqcache[i]==r) {
				this.rqfree[i] = true;
				return;
			}
	},
	envelope : function(str) {
		if (!str)
			return str;
		return Base64.encode(str).rplace("+","%2B");
	},
	deenvelope : function(str) {
		return Base64.decode(str);
	}
};

for (i=0; i<10; i++) {
	request.rqcache[i] = request.transport();
	request.rqfree[i] = true;
}