Get maximum users system information with JavaScript
<p>I'm creating a homepage where I want to keep an open comment field. But in the case that this is abused I want to log as much client information as possible on all the users that makes a post.</p>

<p>So my question is, how can I get the maximum amount of user data from a user with javascript?</p>

<p>In php I can save the $_SERVER variable but is there any similar easy way of doing it in Javascript?
Also if not what data would you recommend to save? Ip, geodata, maybe a username? I don't know how powerful javascript is in getting user system information.</p>
