insert multiple objects into variable (array)

Hello,

 I need to create PS script to which gets logged on users(get-rdusersession | select UserName), puts them into variable $users=@(user1,user2,...,userN) and runs foreach {something} - something like send message and logoff user. But I cannot get the output from command get-rdusersession to the variable. Can someone tell, how to do that? Thank you.

Pete

sfs