Does String.fromCharCode(decimal value) in javascript supports extended characters also

I am using function String.fromCharCode(decimal value), and passing a decimal value to it.

its working fine in terms of English characters, but when i m trying the same to decode for the Japanese characters, it gives me some arbit characters.

can anyone tell me does String.fromCharCode(decimal value) supports extended characters.

No, it doesn't support characters that use two surrogates. MDC has a utility function that is meant to handle this:

// String.fromCharCode() alone cannot get the character at such a high code point
// The following, on the other hand, can return a 4-byte character as well as the 
//   usual 2-byte ones (i.e., it can return a single character which actually has 
//   a string length of 2 instead of 1!)
alert(fixedFromCharCode(0x2F804)); // or 194564 in decimal

function fixedFromCharCode (codePt) {
    if (codePt > 0xFFFF) {
        codePt -= 0x10000;
        return String.fromCharCode(0xD800 + (codePt >> 10), 0xDC00 +
(codePt & 0x3FF));
    }
    else {
        return String.fromCharCode(codePt);
    }
}