function base64_encode (data) {
  // http://kevin.vanzonneveld.net
  // +   original by: Tyler Akins (http://rumkin.com)
  // +   improved by: Bayron Guevara
  // +   improved by: Thunder.m
  // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +   bugfixed by: Pellentesque Malesuada
  // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +   improved by: Rafa? Kukawski (http://kukawski.pl)
  // *     example 1: base64_encode('Kevin van Zonneveld');
  // *     returns 1: 'S2V2aW4gdmFuIFpvbm5ldmVsZA=='
  // mozilla has this native
  // - but breaks in 2.0.0.12!
  //if (typeof this.window['btoa'] === 'function') {
  //    return btoa(data);
  //}
	var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
	var o1, o2, o3, h1, h2, h3, h4, bits, i = 0,
    ac = 0,
    enc = "",
    tmp_arr = [];

	if (!data) {
		return data;
	}

	do { // pack three octets into four hexets
		o1 = data.charCodeAt(i++);
		o2 = data.charCodeAt(i++);
		o3 = data.charCodeAt(i++);

		bits = o1 << 16 | o2 << 8 | o3;

		h1 = bits >> 18 & 0x3f;
		h2 = bits >> 12 & 0x3f;
		h3 = bits >> 6 & 0x3f;
		h4 = bits & 0x3f;

    // use hexets to index into b64, and append result to encoded string
		tmp_arr[ac++] = b64.charAt(h1) + b64.charAt(h2) + b64.charAt(h3) + b64.charAt(h4);
	} while (i < data.length);

	enc = tmp_arr.join('');

	var r = data.length % 3;

	return (r ? enc.slice(0, r - 3) : enc) + '==='.slice(r || 3);

}


function base64_decode (data) {
  // http://kevin.vanzonneveld.net
  // +   original by: Tyler Akins (http://rumkin.com)
  // +   improved by: Thunder.m
  // +      input by: Aman Gupta
  // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +   bugfixed by: Onno Marsman
  // +   bugfixed by: Pellentesque Malesuada
  // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +      input by: Brett Zamir (http://brett-zamir.me)
  // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // *     example 1: base64_decode('S2V2aW4gdmFuIFpvbm5ldmVsZA==');
  // *     returns 1: 'Kevin van Zonneveld'
  // mozilla has this native
  // - but breaks in 2.0.0.12!
  //if (typeof this.window['atob'] === 'function') {
  //    return atob(data);
  //}
	var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
	var o1, o2, o3, h1, h2, h3, h4, bits, i = 0,
    ac = 0,
    dec = "",
    tmp_arr = [];

	if (!data) {
		return data;
	}

	data += '';

	do { // unpack four hexets into three octets using index points in b64
		h1 = b64.indexOf(data.charAt(i++));
		h2 = b64.indexOf(data.charAt(i++));
		h3 = b64.indexOf(data.charAt(i++));
		h4 = b64.indexOf(data.charAt(i++));

		bits = h1 << 18 | h2 << 12 | h3 << 6 | h4;

		o1 = bits >> 16 & 0xff;
		o2 = bits >> 8 & 0xff;
		o3 = bits & 0xff;

		if (h3 == 64) {
			tmp_arr[ac++] = String.fromCharCode(o1);
		} else if (h4 == 64) {
			tmp_arr[ac++] = String.fromCharCode(o1, o2);
		} else {
			tmp_arr[ac++] = String.fromCharCode(o1, o2, o3);
		}
	} while (i < data.length);

	dec = tmp_arr.join('');

	return dec;
}