It doesn’t work reliably or at all.
That is one of the things I fixed in WebLoginPE.
You can set a cookie with a checkbox (name="rememberme") that, if checked will keep the user logged in until they intentionally log out, at which point the cookie will be deleted. The other option is to have a select named "stayloggedin" witch, in the default WebLoginPE login form looks like
<select id="wlpeStayLoggedIn" name="stayloggedin">
<option value="">No</option>
<option value="3600">1 Hour</option>
<option value="86400">1 Day</option>
<option value="604800">1 Week</option>
<option value="2678400">1 Month</option>
<option value="315569260">Forever</option>
</select>
Depending on what the user selects, WebLoginPE keeps them logged in for that time period (obviously the values are in seconds) or until they intentionally log out in which case the cookie is destroyed.
-sD-
Dr. Scotty Delicious, Scientist DFPA.
I have a demo up at
http://demo.scottydelicious.com