function rot13 (string) {
    var aCode = 'a'.charCodeAt();
    var zCode = 'z'.charCodeAt();
    var ACode = 'A'.charCodeAt();
    var ZCode = 'Z'.charCodeAt();
    var result = '';
    for (var c = 0; c < string.length; c++) {
        var charCode = string.charCodeAt(c);
        if (charCode >= aCode && charCode <= zCode)
        charCode = aCode + (charCode - aCode + 13) % 26;
        else if (charCode >= ACode && charCode <= ZCode)
        charCode = ACode + (charCode - ACode + 13) % 26;
        result += String.fromCharCode(charCode);
    }
    return result;
}

function mailto (name) {
    document.write('<a href=\"mailto:' + rot13(name) + '\">');
    document.write(rot13(name) + '<\/a\>');
}