[Typo3] Session trouble

[Alexander Maringer]

Hi,

I have very much trouble with sessions.

I can save data in the session [ 
$GLOBALS['TSFE']->fe_user->setKey('ses','myData', $this->userdata); ] and 
can get the data back .... $GLOBALS['TSFE']->fe_user->getKey(...)

But how can I delete a value of my session??

Thanks a lot

Alexander