Auto Gearbox Oil Level

Hi,
Just been to change the oil (or as much as I can) and filter in my auto box. I have read many posts on this, but have one question. Before I started, the box was still warm and with the engine running I put it through each gear for 1 second. Then I removed the filler plug (to make sure before draining). As I did this, gearbox oil poured out of the filler hole (about 2 litres with the engine running). I was under the impression that with the engine still running then this is how the levels are checked and it should just bead at this point?
I assume that it was overfilled or is there a time limit as to how long you get to check the levels after going through the gears? (ie does the oil run back out of the gears / clutches etc..)
I have just topped it back up for now incase I was doing something wrong! (went through the gears whilst topping up)

start engine pull lever through gears ,put in neutral check level

Doesn't your auto box have a dipstick?

Thanks James. So if after pulling through the gears, leaving engine still running and it still pours out of the filler hole, then chances are it was overfilled? Literally 2 litres came out! Worrying stuff!

Jailon - No, the later ZF gearboxes don't have a dipstick. This would make life too easy!

just go through gears once and what pours out with engine running in neutral is excess ,over filling wont necessarily hurt it ,but correct level is needed for proper functioning