Review this code, for code quality...
<!DOCTYPE html>
<title>Email obfuscator</title>
<style>.email { unicode-bidi: bidi-override; direction: rtl; }</style>
<h1>Email obfuscator</h1>
<p>A kick-ass email obfuscator, inspired by <a href="http://mathiasbynens.be/demo/email-obfuscator#code">Mathias Bynens's <code>obfuscate_email()</code> PHP function</a>. This tool will encode (HTML) and/or reverse (CSS) any email address you enter, making it less vulnerable to spammers who use email harvesting software aka spambots.</p>
<h2>The output</h2>
<p id="preview">(preview will be shown here)</p>
<p><textarea id="output" rows="6" cols="60" onclick="this.select()"></textarea></p>
<h2>The input</h2>
<form name="OBFUSCATOR">
<p><label for="email">Email: <small>(enter the email address to be obfuscated)</small></label> <input type="text" id="email" size="28" autofocus></p>
<p><input id="encode" type="checkbox" checked> <label for="encode">Convert into HTML entities ("encode")</label></p>
<p><input id="reverse" type="checkbox"> <label for="reverse">Reverse using CSS</label></p>
<p><input id="link" type="checkbox"> <label for="link">Create HTML link</label></p>
<p><input type="button" value="Obfuscate This!" onclick="obfuscate_email()"></p>
</form>
<script>
function obfuscate_email() {
var email = document.OBFUSCATOR.email.value,
encodedEmail = "",
output = "";
if (!email) {
alert("Please enter an email address.");
} else {
if (document.OBFUSCATOR.reverse.checked) {
email = email.split("").reverse().join("");
output = "<span class=\"email\">";
}
if (document.OBFUSCATOR.encode.checked) {
for (var i = 0; i < email.length; i++) {
encodedEmail += "&#" + email.charCodeAt(i) + ";";
}
output += encodedEmail;
} else {
output += email;
}
if (document.OBFUSCATOR.reverse.checked) {
output += "</span>";
}
document.getElementById("output").value = document.OBFUSCATOR.link.checked ? "<a href=\"mailto:" + (document.OBFUSCATOR.encode.checked ? encodedEmail : email) + "\">" + output + "</a>" : output;
document.getElementById("preview").innerHTML = document.getElementById("output").value;
}
}
</script>
