function for Base64Decode unable to decode the character €

Question

UTF8 Decode for € not working with the below method.

 

What changes needed to decode in UTF8 For Euro symbol (€). I have tried the escape method before decodeuricomponent. what changes need in the method with out use of escape???

var Base64Decode = function (encoded, escapeChar) {
    try {
        var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";//èéêëàâùìîçò";
        var output = "";
        var chr1, chr2, chr3;
        var enc1, enc2, enc3, enc4;
        var i = 0;

        do {
            enc1 = keyStr.indexOf(encoded.charAt(i++));
            enc2 = keyStr.indexOf(encoded.charAt(i++));
            enc3 = keyStr.indexOf(encoded.charAt(i++));
            enc4 = keyStr.indexOf(encoded.charAt(i++));

            chr1 = (enc1 << 2) | (enc2 >> 4);
            chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
            chr3 = ((enc3 & 3) << 6) | enc4;

            output = output + String.fromCharCode(chr1);

            if (enc3 != 64) {
                output = output + String.fromCharCode(chr2);
            }
            if (enc4 != 64) {
                output = output + String.fromCharCode(chr3);
            }
        } while (i < encoded.length);

        if (escapeChar == undefined) {
            return decodeURIComponent(output);
        }
        else {
            return output;
        }

    } catch (ex) {
    }
};

The output comes like â¬