JavaScript: Decode from Base64

Once again, I will not take credit of this one too...

// ***
// Decode from Base64
// Warning: Do not use for larger content as the loop might take a while
// ***
function base64Decode(data)
{
data = data.replace(/[^a-z0-9\+\/=]/ig, '');
if (typeof(atob) == 'function') return atob(data);
var b64_map = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
var byte1, byte2, byte3;
var ch1, ch2, ch3, ch4;
var result = new Array();
var j=0;
while ((data.length%4) != 0) {
data += '=';
}

for (var i=0; i <data.length; i+=4) {
ch1 = b64_map.indexOf(data.charAt(i));
ch2 = b64_map.indexOf(data.charAt(i+1));
ch3 = b64_map.indexOf(data.charAt(i+2));
ch4 = b64_map.indexOf(data.charAt(i+3));

byte1 = (ch1 <<>> 4);
byte2 = ((ch2 & 15) <<>> 2);
byte3 = ((ch3 & 3) << 6) | ch4;

result[j++] = String.fromCharCode(byte1);
if (ch3 != 64) result[j++] = String.fromCharCode(byte2);
if (ch4 != 64) result[j++] = String.fromCharCode(byte3);
}

return result.join('');
}

JavaScript: Return the NT ID of an user using Shell

// ***
// Returns NT ID of current user
// Note: Would cause an ActiveX warning message if corresponding site is not added in "Trusted Sites" list
// Behavior may also vary with different versions of IE (IE6 vs IE7)
// ***
function getCurrentUserId()
{
var wshell = new ActiveXObject("WScript.Shell");
var userId = wshell.ExpandEnvironmentStrings("%USERNAME%");
return userId;
}

JavaScript: Encode to Base64

Once again, I will not take credit of this one...

// ***
// Encode to Base64
// Warning: Do not use for larger content as the loop might take a while
// ***
function base64Encode(data)
{
if (typeof(btoa) == 'function') return btoa(data);
var b64_map = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
var byte1, byte2, byte3;
var ch1, ch2, ch3, ch4;
var result = new Array();
var j=0;
for (var i=0; i byte1 = data.charCodeAt(i);
byte2 = data.charCodeAt(i+1);
byte3 = data.charCodeAt(i+2);
ch1 = byte1 >> 2;
ch2 = ((byte1 & 3) << 4) | (byte2 >> 4);
ch3 = ((byte2 & 15) << 2) | (byte3 >> 6);
ch4 = byte3 & 63;

if (isNaN(byte2)) {
ch3 = ch4 = 64;
} else if (isNaN(byte3)) {
ch4 = 64;
}

result[j++] = b64_map.charAt(ch1)+b64_map.charAt(ch2)+b64_map.charAt(ch3)+b64_map.charAt(ch4);
}

return result.join('');
}