The fm:IfUserIsDisabled component allows you to check whether or not if a particular user id has been disabled. If it is disabled it will return 1 or true. If the user isn't disabled it will return 0 or false.
<fm:IfUserIsDisabled uid="123456"> User is disabled <fm:Else> User is not disabled </fm:Else> </fm:IfUserIsDisabled>
|uid||Required||N/A||The user ID which should be checked.|