How to print literal unicode string in Javascript?

I have an array containing strings with special unicode characters:

var a = [
    ["a", 33],  
    ["h\u016B", 44],
    ["s\u00EF", 51],
    ...
];

When I loop over this array:

for (i=0;i<a.length;i++) {
    document.write(a[i][0] + "<br />");
}

It prints characters with accents:

a
hù
sô
...

and I want:

a
h\u016B
s\u00EF
...

How can I achieve this in Javascript?

Something like this?

/* Creates a uppercase hex number with at least length digits from a given number */
function fixedHex(number, length){
    var str = number.toString(16).toUpperCase();
    while(str.length < length)
        str = "0" + str;
    return str;
}

/* Creates a unicode literal based on the string */    
function unicodeLiteral(str){
    var i;
    var result = "";
    for( i = 0; i < str.length; ++i){
        /* You should probably replace this by an isASCII test */
        if(str.charCodeAt(i) > 126 || str.charCodeAt(i) < 32)
            result += "\\u" + fixedHex(str.charCodeAt(i),4);
        else
            result += str[i];
    }

    return result;
}

var a = [
    ["a", 33],  
    ["h\u016B", 44],
    ["s\u00EF", 51]
];

var i;
for (i=0;i<a.length;i++) {
    document.write(unicodeLiteral(a[i][0]) + "<br />");
}

Result

a
h\u016B
s\u00EF

JSFiddle