remove string at the beginning
<p>How to remove <code>www.</code> from a beginning of a string in javascript:<br>
e.g. <code>www.test.com</code> → <code>test.com</code><br>
e.g. <code>www.testwww.com</code> → <code>testwww.com</code><br>
e.g. <code>testwww.com</code> → <code>testwww.com</code> (if it doesn't exist)</p>

<p>Regexp or is there a smart function?</p>
