Thanks for your hint
I used it already as you described
but I found the reason :-)
with Jelly Bean tasker can not switch Airplane mode anymore, I had to use secure settings plugin
Tasker seems not to recognize the switch immediatly, so my if-statement don't work
I changed code now, use an own variable, where I store old airplan modus, before switch by secure settings plugin.
Later I use this own variable for if-statement, now task works as wanted perfectly :-)