JavaScript/jQuery encoding/decoding issue

I have text fields where a user can enter any characters. So if a user enters something like

<script>alert('hello')</script>

the data will be saved in the db like

<script>alert('hello')</script>

And when I display this data again we decode it so it appears the way it was entered.

What I am trying to do is create a file with all the characters that a user will be allowed to enter in a text field. The file is defined like this

< &lt;
> &gt;
' &#39;
" &quote;
+ &#43;
¿ &iquest;

Each character and it's code separated by a space in a new line. I wrote a webmethod in a webservice that returns an array.

The code in the service is

public string[] GetCharacters()
        {
            string[] lines = File.ReadAllLines(Server.MapPath("~/scripts/EncodingChars/CharacterList.txt"));
            return lines;
        }

In my script file I am calling an ajax function that returns this array.

function DecodeText() {
    $.ajax({
        type: "POST",
        url: "myService.asmx/GetCharacters",
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: DecodeFileSuccess,
        failure: function (data) {
            alert(data.d);
        }
    });
}

function DecodeFileSuccess(response) {
    var chars = response.d;
    var textFields = $("textarea, input:text").not("input:hidden");

    textFields.each(function (e) {
        if ($(this).val()) {
            var content = $(this).val();
            $.each(chars, function (index, val) {
                var char = val.split(" ");
                content = content.replace(char[1], char[0]);
                $(this).val(content);
            });
        }
    });
}

I am trying to loop the array and replace the encoded value with the actual character. But it is not working. If I do something directly like

content = content.replace(/\&lt;/g, "<");

it works.

What am I doing wrong in the loop below that it is not replacing the encoded values with the special character?

$.each(chars, function (index, val) {
    var char = val.split(" ");
    content = content.replace(char[1], char[0]);
    $(this).val(content);
});

Thanks