Detect whether attached or detached from screen session?

[Sven Hazejager]

Hi all,

I'm using screen to keep some applications open over a remote SSH
connection that sometimes is killed. What I would like to do, is to
somehow find out whether I am logged in (attached) or disconnected
from the screen session.

Reason is that I want procmail to send incoming mail to my BlackBerry
if I'm disconnected, but NOT do that when I'm SSH-ing into my Pine
session.

Using ps to see if Pine is active doesn't work of course, because it
always runs, even when screen is detached...

Any suggestions?

Thanks!

Sven