Greetings!

 I have a web service (ASMX) and in it, a web method that does some work and throws an exception if the input wasn't valid.

throw new Exception(l_errMsg ?? "Invalid Input.");

function GetInputErrorCallback(error)
{
    // Insert the error message into the Forgot Password help window's existing content.
    var errorDiv = document.getElementById('input_error');

    if (errorDiv != null)
        errorDiv.innerHTML = error.get_message();
}

This works great.  However, if one of my error messages that's returned contains a special character, it's displayed incorrectly in the browser.

For example, if the error message were to contain the following:

That input isn’t valid!  (that's an ASCII #146 in there)

It displays this:

That input isn’t valid!

Or:

Do you like Hüsker Dü? (ASCII # 252)

Becomes:

Do you like Hüsker Dü?

The values returned by the web service (in the l_errMsg variable) look fine.  It's just once the client script has a hold of, it displays incorrectly.  How can I fix this?  Thanks in advance.

I don´t think there’s a problem with your webmethod; I think you should set the correct encoding of your page so your client can see the special symbols.

By "page encoding" are you referring to setting the character set via a manner such as this?

Response.Charset = "Windows-1252";

You'll need to set the encoding with something like:

Response.ContentEncoding = System.Text.Encoding.GetEncoding("iso-8859-1");

In my case iso-8859-1 works great for Spanish special symbols.

In my Page_Load() method, I've tried:

Response.ContentEncoding = System.Text.Encoding.GetEncoding("utf-8");

and:

Response.ContentEncoding = System.Text.Encoding.GetEncoding("Windows-1252");

But no luck with either. My error messages that I return from my web service are retrieved from XML files that are encoded with UTF-8:

 <?xml version="1.0" encoding="UTF-8"?>

Is there anything else that I could be missing?  Thanks in advance.

To add, I've noticed that the string only becomes gibberish when it's returned from a thrown exception.  For example, here's a sample web method in my ASMX:

[ScriptMethod]
[WebMethod]
public string MyWebMethod(string input)
{
    if (!ValidInput(input))
    {
        string l_msg = GetErrorMessage();
        throw new Exception(l_msg);
    }
    else
        return input;
}

Back on a web page, I may have something like this:

function GetUserInput()
{
    MyWebServices.MyWebMethod(user_input, OnSuccessCallback, OnFailCallback);
}

function OnSuccessCallback(result)
{
    $get('msg_area').innerHTML = result;
}

function OnFailCallback(error)
{
    $get('err_msg').innerHTML = get_message();
}

If the Web Service succeeds and the OnSuccessCallback function is invoked in the client-side JavaScript, any text with characters (such as "ü", which is ASCII #252), it's displayed properly - no problem.  However, web the Web Service has to throw an exception, thus invoking the OnFailCallback function in the client-side JavaScript, then those same characters are garbled.  Is there something I'm missing?  Thanks in advance.

I managed to find a solution.  I neeed to set the ContentEncoding of the Response to match that of the XML files I was retrieving the message from (UTF-8):

HttpContext.Current.Response.ContentEncoding = Encoding.UTF8;

Thanks.