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);

//«È¤áºÝBase64½s½X
function base64encode(str) {

	//alert('before str=' + str);
	str = Myutf16to8(str);
	//alert('utf16to8 str=' + 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);
	}
	
	//alert('base64encode out=' + out);
    return out;
}

//«È¤áºÝBase64¸Ñ½X
function base64decode(str) {
    var c1, c2, c3, c4;
    var i, len, out;

    len = str.length;
    i = 0;
    out = "";
    while(i < len) {
    
		/* c1 */
		do {
			c1 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
		} while(i < len && c1 == -1);
		if(c1 == -1)
			break;

		/* c2 */
		do {
			c2 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
		} while(i < len && c2 == -1);
		if(c2 == -1)
			break;

		out += String.fromCharCode((c1 << 2) | ((c2 & 0x30) >> 4));

		/* c3 */
		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));

		/* c4 */
		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;
}


//utf16to8
function Myutf16to8(str) {
	//alert('str=' + str);
    var out;
    var i;
    var len;
    var 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;
}

//utf8to16
function Myutf8to16(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:
     // 0xxxxxxx
     out += str.charAt(i-1);
     break;
   case 12: case 13:
     // 110x xxxx   10xx xxxx
     char2 = str.charCodeAt(i++);
     out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
     break;
   case 14:
     // 1110 xxxx  10xx xxxx  10xx xxxx
     char2 = str.charCodeAt(i++);
     char3 = str.charCodeAt(i++);
     out += String.fromCharCode(((c & 0x0F) << 12) |
        ((char2 & 0x3F) << 6) |
        ((char3 & 0x3F) << 0));
     break;
 }
    }

    return out;
}