/**
 * alert(Base64Util.Base64Encode("aa"));
 * alert(Base64Util.Base64Decode("emhhbmd6aGlqdW4="));
 */
var Base64Util = new function() {
	this.Base64Encode = function(str) {
		return base64encode(utf16to8(str));
	};

	this.Base64Decode = function(str) {
		return utf8to16(base64decode(str))
	};

	var base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
	var base64DecodeChars = new Array(-1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
			-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
			-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62,
			-1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1,
			-1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
			15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1,
			26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42,
			43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1);
	var base64encode = function(str) {
		var out, i, len;
		var c1, c2, c3;
		len = str.length;
		i = 0;
		out = "";
		while (i < len) {
			c1 = str.charCodeAt(i++) & 0xff;
			if (i == len) {
				out += base64EncodeChars.charAt(c1 >> 2);
				out += base64EncodeChars.charAt((c1 & 0x3) << 4);
				out += "==";
				break;
			}
			c2 = str.charCodeAt(i++);
			if (i == len) {
				out += base64EncodeChars.charAt(c1 >> 2);
				out += base64EncodeChars.charAt(((c1 & 0x3) << 4)
						| ((c2 & 0xF0) >> 4));
				out += base64EncodeChars.charAt((c2 & 0xF) << 2);
				out += "=";
				break;
			}
			c3 = str.charCodeAt(i++);
			out += base64EncodeChars.charAt(c1 >> 2);
			out += base64EncodeChars.charAt(((c1 & 0x3) << 4)
					| ((c2 & 0xF0) >> 4));
			out += base64EncodeChars.charAt(((c2 & 0xF) << 2)
					| ((c3 & 0xC0) >> 6));
			out += base64EncodeChars.charAt(c3 & 0x3F);
		}
		return out;
	};

	var base64decode = function(str) {
		var c1, c2, c3, c4;
		var i, len, out;
		len = str.length;
		i = 0;
		out = "";
		while (i < len) {
			do {
				c1 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
			} while (i < len && c1 == -1);
			if (c1 == -1)
				break;
			do {
				c2 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
			} while (i < len && c2 == -1);
			if (c2 == -1)
				break;
			out += String.fromCharCode((c1 << 2) | ((c2 & 0x30) >> 4));
			do {
				c3 = str.charCodeAt(i++) & 0xff;
				if (c3 == 61)
					return out;
				c3 = base64DecodeChars[c3];
			} while (i < len && c3 == -1);
			if (c3 == -1)
				break;
			out += String.fromCharCode(((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2));
			do {
				c4 = str.charCodeAt(i++) & 0xff;
				if (c4 == 61)
					return out;
				c4 = base64DecodeChars[c4];
			} while (i < len && c4 == -1);
			if (c4 == -1)
				break;
			out += String.fromCharCode(((c3 & 0x03) << 6) | c4);
		}
		return out;
	};
	var utf16to8 = function(str) {
		var out, i, len, c;
		out = "";
		len = str.length;
		for (i = 0; i < len; i++) {
			c = str.charCodeAt(i);
			if ((c >= 0x0001) && (c <= 0x007F)) {
				out += str.charAt(i);
			} else if (c > 0x07FF) {
				out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));
				out += String.fromCharCode(0x80 | ((c >> 6) & 0x3F));
				out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
			} else {
				out += String.fromCharCode(0xC0 | ((c >> 6) & 0x1F));
				out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));
			}
		}
		return out;
	};
	var utf8to16 = function(str) {
		var out, i, len, c;
		var char2, char3;
		out = "";
		len = str.length;
		i = 0;
		while (i < len) {
			c = str.charCodeAt(i++);
			switch (c >> 4) {
			case 0:
			case 1:
			case 2:
			case 3:
			case 4:
			case 5:
			case 6:
			case 7:
				out += str.charAt(i - 1);
				break;
			case 12:
			case 13:
				char2 = str.charCodeAt(i++);
				out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
				break;
			case 14:
				char2 = str.charCodeAt(i++);
				char3 = str.charCodeAt(i++);
				out += String.fromCharCode(((c & 0x0F) << 12)
						| ((char2 & 0x3F) << 6) | ((char3 & 0x3F) << 0));
				break;
			}
		}
		return out;
	}
}